diff --git a/cmd/uptop/keycache_test.go b/cmd/uptop/keycache_test.go
index dc10640..09af153 100644
--- a/cmd/uptop/keycache_test.go
+++ b/cmd/uptop/keycache_test.go
@@ -9,22 +9,21 @@ import (
 	"time"
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
-	"gitea.lerkolabs.com/lerkolabs/uptop/internal/store"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/store/storetest"
 
 	"github.com/charmbracelet/ssh"
 	gossh "golang.org/x/crypto/ssh"
 )
 
-// kcMockStore implements only what keyCache and userInvalidatingStore touch;
-// any other Store method panics via the embedded nil interface.
+// kcMockStore embeds BaseMock for default no-ops; only GetAllUsers is
+// overridden because the tests mutate users/err between calls.
 type kcMockStore struct {
-	store.Store
+	storetest.BaseMock
 	users []models.User
 	err   error
 }
 
 func (m *kcMockStore) GetAllUsers(_ context.Context) ([]models.User, error) { return m.users, m.err }
-func (m *kcMockStore) DeleteUser(_ context.Context, _ int) error            { return nil }
 
 func testKey(t *testing.T) (string, ssh.PublicKey) {
 	t.Helper()
diff --git a/internal/cluster/cluster_test.go b/internal/cluster/cluster_test.go
index a8ea1dd..bb36f4a 100644
--- a/internal/cluster/cluster_test.go
+++ b/internal/cluster/cluster_test.go
@@ -12,100 +12,13 @@ import (
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/monitor"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/store/storetest"
 )
 
-// --- Mock Store (minimal, for monitor.NewEngine) ---
-
 type mockStore struct {
-	sites []models.Site
+	storetest.BaseMock
 }
 
-func (m *mockStore) Init(_ context.Context) error                                 { return nil }
-func (m *mockStore) GetSites(_ context.Context) ([]models.Site, error)            { return m.sites, nil }
-func (m *mockStore) AddSite(_ context.Context, _ models.Site) error               { return nil }
-func (m *mockStore) UpdateSite(_ context.Context, _ models.Site) error            { return nil }
-func (m *mockStore) UpdateSitePaused(_ context.Context, _ int, _ bool) error      { return nil }
-func (m *mockStore) DeleteSite(_ context.Context, _ int) error                    { return nil }
-func (m *mockStore) GetAllAlerts(_ context.Context) ([]models.AlertConfig, error) { return nil, nil }
-func (m *mockStore) GetAlert(_ context.Context, _ int) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
-}
-func (m *mockStore) AddAlert(_ context.Context, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *mockStore) UpdateAlert(_ context.Context, _ int, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *mockStore) DeleteAlert(_ context.Context, _ int) error                    { return nil }
-func (m *mockStore) GetAllUsers(_ context.Context) ([]models.User, error)          { return nil, nil }
-func (m *mockStore) AddUser(_ context.Context, _ string, _ string, _ string) error { return nil }
-func (m *mockStore) UpdateUser(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *mockStore) DeleteUser(_ context.Context, _ int) error                 { return nil }
-func (m *mockStore) SaveCheck(_ context.Context, _ int, _ int64, _ bool) error { return nil }
-func (m *mockStore) SaveCheckFromNode(_ context.Context, _ int, _ string, _ int64, _ bool) error {
-	return nil
-}
-func (m *mockStore) LoadAllHistory(_ context.Context, _ int) (map[int][]models.CheckRecord, error) {
-	return nil, nil
-}
-func (m *mockStore) ExportData(_ context.Context) (models.Backup, error) { return models.Backup{}, nil }
-func (m *mockStore) ImportData(_ context.Context, _ models.Backup) error { return nil }
-func (m *mockStore) GetSiteByName(_ context.Context, _ string) (models.Site, error) {
-	return models.Site{}, nil
-}
-func (m *mockStore) GetAlertByName(_ context.Context, _ string) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
-}
-func (m *mockStore) AddSiteReturningID(_ context.Context, _ models.Site) (int, error) { return 0, nil }
-func (m *mockStore) AddAlertReturningID(_ context.Context, _ string, _ string, _ map[string]string) (int, error) {
-	return 0, nil
-}
-func (m *mockStore) RegisterNode(_ context.Context, _ models.ProbeNode) error { return nil }
-func (m *mockStore) GetNode(_ context.Context, _ string) (models.ProbeNode, error) {
-	return models.ProbeNode{}, nil
-}
-func (m *mockStore) GetAllNodes(_ context.Context) ([]models.ProbeNode, error) { return nil, nil }
-func (m *mockStore) UpdateNodeLastSeen(_ context.Context, _ string) error      { return nil }
-func (m *mockStore) DeleteNode(_ context.Context, _ string) error              { return nil }
-func (m *mockStore) LoadAlertHealth(_ context.Context) (map[int]models.AlertHealthRecord, error) {
-	return nil, nil
-}
-func (m *mockStore) SaveAlertHealth(_ context.Context, _ models.AlertHealthRecord) error { return nil }
-func (m *mockStore) SaveLog(_ context.Context, _ string) error                           { return nil }
-func (m *mockStore) PruneLogs(_ context.Context) error                                   { return nil }
-func (m *mockStore) PruneCheckHistory(_ context.Context) error                           { return nil }
-func (m *mockStore) PruneStateChanges(_ context.Context) error                           { return nil }
-func (m *mockStore) LoadLogs(_ context.Context, _ int) ([]string, error)                 { return nil, nil }
-func (m *mockStore) GetActiveMaintenanceWindows(_ context.Context) ([]models.MaintenanceWindow, error) {
-	return nil, nil
-}
-func (m *mockStore) GetAllMaintenanceWindows(_ context.Context, _ int) ([]models.MaintenanceWindow, error) {
-	return nil, nil
-}
-func (m *mockStore) AddMaintenanceWindow(_ context.Context, _ models.MaintenanceWindow) error {
-	return nil
-}
-func (m *mockStore) EndMaintenanceWindow(_ context.Context, _ int) error    { return nil }
-func (m *mockStore) DeleteMaintenanceWindow(_ context.Context, _ int) error { return nil }
-func (m *mockStore) PruneExpiredMaintenanceWindows(_ context.Context, _ time.Duration) (int64, error) {
-	return 0, nil
-}
-func (m *mockStore) IsMonitorInMaintenance(_ context.Context, _ int) (bool, error) { return false, nil }
-func (m *mockStore) GetPreference(_ context.Context, _ string) (string, error)     { return "", nil }
-func (m *mockStore) SetPreference(_ context.Context, _ string, _ string) error     { return nil }
-func (m *mockStore) SaveStateChange(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *mockStore) GetStateChanges(_ context.Context, _ int, _ int) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) GetStateChangesSince(_ context.Context, _ int, _ time.Time) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) Close() error { return nil }
-
 // --- Cluster Start Tests ---
 
 func TestStart_LeaderMode(t *testing.T) {
diff --git a/internal/cluster/probe.go b/internal/cluster/probe.go
index 41828ae..93dbf66 100644
--- a/internal/cluster/probe.go
+++ b/internal/cluster/probe.go
@@ -157,7 +157,7 @@ loop:
 			results = append(results, probeResultItem{
 				SiteID:      s.ID,
 				LatencyNs:   cr.LatencyNs,
-				IsUp:        cr.Status == "UP",
+				IsUp:        cr.Status == string(models.StatusUp),
 				ErrorReason: cr.ErrorReason,
 			})
 			mu.Unlock()
diff --git a/internal/metrics/prometheus.go b/internal/metrics/prometheus.go
index 05446f4..235b152 100644
--- a/internal/metrics/prometheus.go
+++ b/internal/metrics/prometheus.go
@@ -2,11 +2,12 @@ package metrics
 
 import (
 	"fmt"
-	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
-	"gitea.lerkolabs.com/lerkolabs/uptop/internal/monitor"
 	"net/http"
 	"sort"
 	"strings"
+
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/monitor"
 )
 
 func Handler(eng *monitor.Engine) http.HandlerFunc {
@@ -19,7 +20,7 @@ func Handler(eng *monitor.Engine) http.HandlerFunc {
 		writeHelp(&b, "uptop_monitor_up", "gauge", "Whether the monitor is up (1) or down (0).")
 		for _, s := range sites {
 			val := 0
-			if s.Status == "UP" {
+			if s.Status == models.StatusUp {
 				val = 1
 			}
 			writeGauge(&b, "uptop_monitor_up", labels(s), float64(val))
diff --git a/internal/metrics/prometheus_test.go b/internal/metrics/prometheus_test.go
index 9352bc4..ccf3d0f 100644
--- a/internal/metrics/prometheus_test.go
+++ b/internal/metrics/prometheus_test.go
@@ -10,97 +10,17 @@ import (
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/monitor"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/store/storetest"
 )
 
 type mockStore struct {
+	storetest.BaseMock
 	sites []models.Site
 }
 
-func (m *mockStore) Init(_ context.Context) error                                 { return nil }
-func (m *mockStore) GetSites(_ context.Context) ([]models.Site, error)            { return m.sites, nil }
-func (m *mockStore) AddSite(_ context.Context, _ models.Site) error               { return nil }
-func (m *mockStore) UpdateSite(_ context.Context, _ models.Site) error            { return nil }
-func (m *mockStore) UpdateSitePaused(_ context.Context, _ int, _ bool) error      { return nil }
-func (m *mockStore) DeleteSite(_ context.Context, _ int) error                    { return nil }
-func (m *mockStore) GetAllAlerts(_ context.Context) ([]models.AlertConfig, error) { return nil, nil }
-func (m *mockStore) GetAlert(_ context.Context, _ int) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
+func (m *mockStore) GetSites(_ context.Context) ([]models.Site, error) {
+	return m.sites, nil
 }
-func (m *mockStore) AddAlert(_ context.Context, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *mockStore) UpdateAlert(_ context.Context, _ int, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *mockStore) DeleteAlert(_ context.Context, _ int) error                    { return nil }
-func (m *mockStore) GetAllUsers(_ context.Context) ([]models.User, error)          { return nil, nil }
-func (m *mockStore) AddUser(_ context.Context, _ string, _ string, _ string) error { return nil }
-func (m *mockStore) UpdateUser(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *mockStore) DeleteUser(_ context.Context, _ int) error                 { return nil }
-func (m *mockStore) SaveCheck(_ context.Context, _ int, _ int64, _ bool) error { return nil }
-func (m *mockStore) LoadAllHistory(_ context.Context, _ int) (map[int][]models.CheckRecord, error) {
-	return nil, nil
-}
-func (m *mockStore) ExportData(_ context.Context) (models.Backup, error) { return models.Backup{}, nil }
-func (m *mockStore) ImportData(_ context.Context, _ models.Backup) error { return nil }
-func (m *mockStore) GetSiteByName(_ context.Context, _ string) (models.Site, error) {
-	return models.Site{}, nil
-}
-func (m *mockStore) GetAlertByName(_ context.Context, _ string) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
-}
-func (m *mockStore) AddSiteReturningID(_ context.Context, _ models.Site) (int, error) { return 0, nil }
-func (m *mockStore) AddAlertReturningID(_ context.Context, _ string, _ string, _ map[string]string) (int, error) {
-	return 0, nil
-}
-func (m *mockStore) SaveCheckFromNode(_ context.Context, _ int, _ string, _ int64, _ bool) error {
-	return nil
-}
-func (m *mockStore) RegisterNode(_ context.Context, _ models.ProbeNode) error { return nil }
-func (m *mockStore) GetNode(_ context.Context, _ string) (models.ProbeNode, error) {
-	return models.ProbeNode{}, nil
-}
-func (m *mockStore) GetAllNodes(_ context.Context) ([]models.ProbeNode, error) { return nil, nil }
-func (m *mockStore) UpdateNodeLastSeen(_ context.Context, _ string) error      { return nil }
-func (m *mockStore) DeleteNode(_ context.Context, _ string) error              { return nil }
-func (m *mockStore) LoadAlertHealth(_ context.Context) (map[int]models.AlertHealthRecord, error) {
-	return nil, nil
-}
-func (m *mockStore) SaveAlertHealth(_ context.Context, _ models.AlertHealthRecord) error { return nil }
-func (m *mockStore) SaveLog(_ context.Context, _ string) error                           { return nil }
-func (m *mockStore) PruneLogs(_ context.Context) error                                   { return nil }
-func (m *mockStore) PruneCheckHistory(_ context.Context) error                           { return nil }
-func (m *mockStore) PruneStateChanges(_ context.Context) error                           { return nil }
-func (m *mockStore) LoadLogs(_ context.Context, _ int) ([]string, error)                 { return nil, nil }
-func (m *mockStore) GetActiveMaintenanceWindows(_ context.Context) ([]models.MaintenanceWindow, error) {
-	return nil, nil
-}
-func (m *mockStore) GetAllMaintenanceWindows(_ context.Context, _ int) ([]models.MaintenanceWindow, error) {
-	return nil, nil
-}
-func (m *mockStore) AddMaintenanceWindow(_ context.Context, _ models.MaintenanceWindow) error {
-	return nil
-}
-func (m *mockStore) EndMaintenanceWindow(_ context.Context, _ int) error    { return nil }
-func (m *mockStore) DeleteMaintenanceWindow(_ context.Context, _ int) error { return nil }
-func (m *mockStore) PruneExpiredMaintenanceWindows(_ context.Context, _ time.Duration) (int64, error) {
-	return 0, nil
-}
-func (m *mockStore) IsMonitorInMaintenance(_ context.Context, _ int) (bool, error) { return false, nil }
-func (m *mockStore) GetPreference(_ context.Context, _ string) (string, error)     { return "", nil }
-func (m *mockStore) SetPreference(_ context.Context, _ string, _ string) error     { return nil }
-func (m *mockStore) SaveStateChange(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *mockStore) GetStateChanges(_ context.Context, _ int, _ int) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) GetStateChangesSince(_ context.Context, _ int, _ time.Time) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) Close() error { return nil }
 
 func TestMetricsHandler(t *testing.T) {
 	ms := &mockStore{
diff --git a/internal/models/models.go b/internal/models/models.go
index 98c1be5..668b9dd 100644
--- a/internal/models/models.go
+++ b/internal/models/models.go
@@ -28,7 +28,7 @@ type Site struct {
 	Regions        string
 
 	FailureCount    int
-	Status          string
+	Status          Status
 	StatusCode      int
 	Latency         time.Duration
 	CertExpiry      time.Time
diff --git a/internal/models/status.go b/internal/models/status.go
new file mode 100644
index 0000000..50275c1
--- /dev/null
+++ b/internal/models/status.go
@@ -0,0 +1,18 @@
+package models
+
+type Status string
+
+const (
+	StatusUp      Status = "UP"
+	StatusDown    Status = "DOWN"
+	StatusPending Status = "PENDING"
+	StatusLate    Status = "LATE"
+	StatusStale   Status = "STALE"
+	StatusSSLExp  Status = "SSL EXP"
+)
+
+func (s Status) IsBroken() bool {
+	return s == StatusDown || s == StatusSSLExp
+}
+
+func (s Status) String() string { return string(s) }
diff --git a/internal/monitor/checker.go b/internal/monitor/checker.go
index 48abc97..13abce2 100644
--- a/internal/monitor/checker.go
+++ b/internal/monitor/checker.go
@@ -47,7 +47,7 @@ func RunCheck(ctx context.Context, site models.Site, strict, insecure *http.Clie
 			if ips, err := net.LookupIP(host); err == nil {
 				for _, ip := range ips {
 					if isPrivateIP(ip) {
-						return CheckResult{SiteID: site.ID, Status: "DOWN", ErrorReason: "target resolves to private IP"}
+						return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), ErrorReason: "target resolves to private IP"}
 					}
 				}
 			}
@@ -64,7 +64,7 @@ func RunCheck(ctx context.Context, site models.Site, strict, insecure *http.Clie
 	case "dns":
 		return runDNSCheck(ctx, site)
 	default:
-		return CheckResult{SiteID: site.ID, Status: "DOWN", ErrorReason: "unsupported monitor type: " + site.Type}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), ErrorReason: "unsupported monitor type: " + site.Type}
 	}
 }
 
@@ -80,7 +80,7 @@ func runHTTPCheck(ctx context.Context, site models.Site, strict, insecure *http.
 
 	req, err := http.NewRequestWithContext(ctx, method, site.URL, nil)
 	if err != nil {
-		return CheckResult{SiteID: site.ID, Status: "DOWN", ErrorReason: "invalid request: " + err.Error()}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), ErrorReason: "invalid request: " + err.Error()}
 	}
 
 	client := strict
@@ -94,12 +94,12 @@ func runHTTPCheck(ctx context.Context, site models.Site, strict, insecure *http.
 
 	result := CheckResult{
 		SiteID:    site.ID,
-		Status:    "UP",
+		Status:    string(models.StatusUp),
 		LatencyNs: latency.Nanoseconds(),
 	}
 
 	if err != nil {
-		result.Status = "DOWN"
+		result.Status = string(models.StatusDown)
 		result.ErrorReason = truncateError(err.Error(), maxErrorLength)
 		return result
 	}
@@ -107,7 +107,7 @@ func runHTTPCheck(ctx context.Context, site models.Site, strict, insecure *http.
 
 	result.StatusCode = resp.StatusCode
 	if !isCodeAccepted(resp.StatusCode, site.AcceptedCodes) {
-		result.Status = "DOWN"
+		result.Status = string(models.StatusDown)
 		expected := site.AcceptedCodes
 		if expected == "" {
 			expected = defaultAcceptedCodes
@@ -120,7 +120,7 @@ func runHTTPCheck(ctx context.Context, site models.Site, strict, insecure *http.
 		cert := resp.TLS.PeerCertificates[0]
 		result.CertExpiry = cert.NotAfter
 		if time.Now().After(cert.NotAfter) {
-			result.Status = "SSL EXP"
+			result.Status = string(models.StatusSSLExp)
 			result.ErrorReason = "SSL certificate expired"
 		}
 	}
@@ -136,7 +136,7 @@ func runPingCheck(_ context.Context, site models.Site) CheckResult {
 
 	pinger, err := probing.NewPinger(host)
 	if err != nil {
-		return CheckResult{SiteID: site.ID, Status: "DOWN", ErrorReason: "ping setup: " + err.Error()}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), ErrorReason: "ping setup: " + err.Error()}
 	}
 	pinger.Count = 1
 	pinger.Timeout = siteTimeout(site)
@@ -147,14 +147,14 @@ func runPingCheck(_ context.Context, site models.Site) CheckResult {
 	latency := time.Since(start)
 
 	if err != nil {
-		return CheckResult{SiteID: site.ID, Status: "DOWN", LatencyNs: latency.Nanoseconds(), ErrorReason: "ping failed: " + err.Error()}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), LatencyNs: latency.Nanoseconds(), ErrorReason: "ping failed: " + err.Error()}
 	}
 	if pinger.Statistics().PacketsRecv == 0 {
-		return CheckResult{SiteID: site.ID, Status: "DOWN", LatencyNs: latency.Nanoseconds(), ErrorReason: "no ICMP response"}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), LatencyNs: latency.Nanoseconds(), ErrorReason: "no ICMP response"}
 	}
 
 	stats := pinger.Statistics()
-	return CheckResult{SiteID: site.ID, Status: "UP", LatencyNs: stats.AvgRtt.Nanoseconds()}
+	return CheckResult{SiteID: site.ID, Status: string(models.StatusUp), LatencyNs: stats.AvgRtt.Nanoseconds()}
 }
 
 func runPortCheck(_ context.Context, site models.Site) CheckResult {
@@ -170,10 +170,10 @@ func runPortCheck(_ context.Context, site models.Site) CheckResult {
 	latency := time.Since(start)
 
 	if err != nil {
-		return CheckResult{SiteID: site.ID, Status: "DOWN", LatencyNs: latency.Nanoseconds(), ErrorReason: truncateError(err.Error(), maxErrorLength)}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), LatencyNs: latency.Nanoseconds(), ErrorReason: truncateError(err.Error(), maxErrorLength)}
 	}
 	_ = conn.Close()
-	return CheckResult{SiteID: site.ID, Status: "UP", LatencyNs: latency.Nanoseconds()}
+	return CheckResult{SiteID: site.ID, Status: string(models.StatusUp), LatencyNs: latency.Nanoseconds()}
 }
 
 func runDNSCheck(_ context.Context, site models.Site) CheckResult {
@@ -221,12 +221,12 @@ func runDNSCheck(_ context.Context, site models.Site) CheckResult {
 	latency := time.Since(start)
 
 	if err != nil {
-		return CheckResult{SiteID: site.ID, Status: "DOWN", LatencyNs: latency.Nanoseconds(), ErrorReason: "DNS query failed: " + err.Error()}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), LatencyNs: latency.Nanoseconds(), ErrorReason: "DNS query failed: " + err.Error()}
 	}
 	if r.Rcode != dns.RcodeSuccess {
-		return CheckResult{SiteID: site.ID, Status: "DOWN", StatusCode: r.Rcode, LatencyNs: latency.Nanoseconds(), ErrorReason: "DNS RCODE: " + dns.RcodeToString[r.Rcode]}
+		return CheckResult{SiteID: site.ID, Status: string(models.StatusDown), StatusCode: r.Rcode, LatencyNs: latency.Nanoseconds(), ErrorReason: "DNS RCODE: " + dns.RcodeToString[r.Rcode]}
 	}
-	return CheckResult{SiteID: site.ID, Status: "UP", LatencyNs: latency.Nanoseconds()}
+	return CheckResult{SiteID: site.ID, Status: string(models.StatusUp), LatencyNs: latency.Nanoseconds()}
 }
 
 func siteTimeout(site models.Site) time.Duration {
diff --git a/internal/monitor/monitor.go b/internal/monitor/monitor.go
index c9ae786..ff7cca3 100644
--- a/internal/monitor/monitor.go
+++ b/internal/monitor/monitor.go
@@ -334,7 +334,7 @@ func (e *Engine) RecordHeartbeat(token string) bool {
 	}
 
 	var (
-		prevStatus string
+		prevStatus models.Status
 		name       string
 		alertID    int
 		downSince  time.Time
@@ -346,12 +346,12 @@ func (e *Engine) RecordHeartbeat(token string) bool {
 		downSince = s.StatusChangedAt // captured before mutation = when it went down
 
 		s.LastCheck = time.Now()
-		s.Status = "UP"
+		s.Status = models.StatusUp
 		s.FailureCount = 0
 		s.Latency = 0
 		s.LastError = ""
 		s.LastSuccessAt = time.Now()
-		if prevStatus != "UP" {
+		if prevStatus != models.StatusUp {
 			s.StatusChangedAt = time.Now()
 		}
 	})
@@ -360,13 +360,13 @@ func (e *Engine) RecordHeartbeat(token string) bool {
 	}
 
 	switch prevStatus {
-	case "PENDING":
+	case models.StatusPending:
 		e.AddLog(fmt.Sprintf("Push Monitor '%s' received first heartbeat", name))
-	case "LATE":
+	case models.StatusLate:
 		e.AddLog(fmt.Sprintf("Push Monitor '%s' heartbeat arrived (was late)", name))
-	case "STALE":
+	case models.StatusStale:
 		e.AddLog(fmt.Sprintf("Push Monitor '%s' heartbeat arrived (was stale)", name))
-	case "DOWN":
+	case models.StatusDown:
 		downDur := ""
 		if !downSince.IsZero() {
 			downDur = fmt.Sprintf(" (was down %s)", fmtDurationShort(time.Since(downSince)))
@@ -375,8 +375,8 @@ func (e *Engine) RecordHeartbeat(token string) bool {
 		go e.triggerAlert(alertID, "✅ RECOVERY", fmt.Sprintf("Push Monitor '%s' is receiving heartbeats.%s", name, downDur))
 	}
 
-	if prevStatus != "UP" && prevStatus != "PENDING" {
-		e.enqueueWrite(writeStateChange{siteID: targetID, fromStatus: prevStatus, toStatus: "UP"})
+	if prevStatus != models.StatusUp && prevStatus != models.StatusPending {
+		e.enqueueWrite(writeStateChange{siteID: targetID, fromStatus: string(prevStatus), toStatus: string(models.StatusUp)})
 	}
 
 	return true
@@ -434,12 +434,12 @@ func (e *Engine) Start(ctx context.Context) {
 				e.mu.RUnlock()
 				if !exists {
 					e.mu.Lock()
-					s.Status = "PENDING"
+					s.Status = models.StatusPending
 					if h, ok := e.GetHistory(s.ID); ok && len(h.Statuses) > 0 {
 						if h.Statuses[len(h.Statuses)-1] {
-							s.Status = "UP"
+							s.Status = models.StatusUp
 						} else {
-							s.Status = "DOWN"
+							s.Status = models.StatusDown
 						}
 						if len(h.Latencies) > 0 {
 							s.Latency = h.Latencies[len(h.Latencies)-1]
@@ -686,7 +686,7 @@ func (e *Engine) checkByID(ctx context.Context, id int) {
 }
 
 func (e *Engine) checkPush(_ context.Context, site models.Site) {
-	if site.Status == "PENDING" {
+	if site.Status == models.StatusPending {
 		return
 	}
 
@@ -702,16 +702,16 @@ func (e *Engine) checkPush(_ context.Context, site models.Site) {
 	now := time.Now()
 
 	if now.After(graceEnd) {
-		if site.Status != "DOWN" {
-			e.handleStatusChange(site, "DOWN", 0, 0, "heartbeat missed")
+		if site.Status != models.StatusDown {
+			e.handleStatusChange(site, string(models.StatusDown), 0, 0, "heartbeat missed")
 		}
 	} else if now.After(staleMark) {
-		if site.Status != "STALE" {
-			e.handleStatusChange(site, "STALE", 0, 0, "heartbeat stale")
+		if site.Status != models.StatusStale {
+			e.handleStatusChange(site, string(models.StatusStale), 0, 0, "heartbeat stale")
 		}
 	} else if now.After(overdue) {
-		if site.Status != "LATE" {
-			e.handleStatusChange(site, "LATE", 0, 0, "heartbeat overdue")
+		if site.Status != models.StatusLate {
+			e.handleStatusChange(site, string(models.StatusLate), 0, 0, "heartbeat overdue")
 		}
 	}
 }
@@ -727,9 +727,10 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 	}
 
 	inMaint := e.isInMaintenance(snap.ID)
+	status := models.Status(rawStatus)
 
 	var (
-		prev, next            string
+		prev, next            models.Status
 		name, typ             string
 		alertID               int
 		failCount, maxRetries int
@@ -745,7 +746,7 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 	_, exists := e.applyState(snap.ID, func(s *models.Site) {
 		// A non-UP result computed from a stale snapshot must not override a
 		// heartbeat (or newer check) that landed while we were evaluating.
-		if rawStatus != "UP" && s.LastCheck.After(snap.LastCheck) {
+		if status != models.StatusUp && s.LastCheck.After(snap.LastCheck) {
 			skipped = true
 			return
 		}
@@ -764,24 +765,24 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 		s.HasSSL = snap.HasSSL
 		s.CertExpiry = snap.CertExpiry
 		s.LastError = errorReason
-		if rawStatus == "UP" {
+		if status == models.StatusUp {
 			s.LastSuccessAt = time.Now()
 			s.LastError = ""
 		}
 
 		// Status + failure-count transition, based on the CURRENT live status.
-		if rawStatus == "UP" {
+		if status == models.StatusUp {
 			s.FailureCount = 0
-			s.Status = "UP"
+			s.Status = models.StatusUp
 		} else {
 			if s.FailureCount <= s.MaxRetries {
 				s.FailureCount++
 			}
 			if s.FailureCount > s.MaxRetries {
-				if s.Status != rawStatus {
+				if s.Status != status {
 					confirmedDown = true
 				}
-				s.Status = rawStatus
+				s.Status = status
 				s.FailureCount = s.MaxRetries + 1
 			} else {
 				failedCheck = true
@@ -789,16 +790,16 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 		}
 		failCount = s.FailureCount
 
-		if s.Status != prev && prev != "PENDING" {
+		if s.Status != prev && prev != models.StatusPending {
 			s.StatusChangedAt = time.Now()
-		} else if s.StatusChangedAt.IsZero() && s.Status != "PENDING" {
+		} else if s.StatusChangedAt.IsZero() && s.Status != models.StatusPending {
 			s.StatusChangedAt = time.Now()
 		}
 
 		// SSL expiry warning (fresh HasSSL/CertExpiry + config threshold).
 		if typ == "http" && s.CheckSSL && s.HasSSL {
 			days := int(time.Until(s.CertExpiry).Hours() / 24)
-			if days <= s.ExpiryThreshold && !s.SentSSLWarning && rawStatus != "SSL EXP" {
+			if days <= s.ExpiryThreshold && !s.SentSSLWarning && status != models.StatusSSLExp {
 				sslWarnFire = true
 				sslDays = days
 				s.SentSSLWarning = true
@@ -815,7 +816,7 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 		return
 	}
 
-	e.recordCheck(snap.ID, latency, rawStatus == "UP")
+	e.recordCheck(snap.ID, latency, status == models.StatusUp)
 
 	if confirmedDown {
 		if errorReason != "" {
@@ -827,8 +828,8 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 		e.AddLog(fmt.Sprintf("Monitor '%s' failed check %d/%d", name, failCount, maxRetries))
 	}
 
-	if changed && prev != "PENDING" {
-		e.enqueueWrite(writeStateChange{siteID: snap.ID, fromStatus: prev, toStatus: next, reason: errorReason})
+	if changed && prev != models.StatusPending {
+		e.enqueueWrite(writeStateChange{siteID: snap.ID, fromStatus: string(prev), toStatus: string(next), reason: errorReason})
 	}
 
 	if sslWarnFire {
@@ -839,13 +840,11 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 		}
 	}
 
-	isBroken := func(s string) bool { return s == "DOWN" || s == "SSL EXP" }
-
-	if prev == "UP" && next == "LATE" {
+	if prev == models.StatusUp && next == models.StatusLate {
 		e.AddLog(fmt.Sprintf("Monitor '%s' heartbeat overdue", name))
 	}
 
-	if !isBroken(prev) && isBroken(next) && next != "PENDING" {
+	if !prev.IsBroken() && next.IsBroken() && next != models.StatusPending {
 		if inMaint {
 			e.AddLog(fmt.Sprintf("Monitor '%s' is DOWN (alerts suppressed — maintenance)", name))
 		} else {
@@ -859,7 +858,7 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 			e.triggerAlert(alertID, "🚨 ALERT", msg)
 		}
 	}
-	if isBroken(prev) && next == "UP" {
+	if prev.IsBroken() && next == models.StatusUp {
 		downDur := ""
 		if !downSince.IsZero() {
 			downDur = fmt.Sprintf(" (was down %s)", fmtDurationShort(time.Since(downSince)))
@@ -869,7 +868,7 @@ func (e *Engine) handleStatusChange(snap models.Site, rawStatus string, code int
 			e.triggerAlert(alertID, "✅ RECOVERY", fmt.Sprintf("Monitor '%s' is UP%s", name, downDur))
 		}
 	}
-	if prev == "LATE" && next == "UP" && !isBroken(prev) {
+	if prev == models.StatusLate && next == models.StatusUp && !prev.IsBroken() {
 		e.AddLog(fmt.Sprintf("Monitor '%s' heartbeat arrived (was late)", name))
 	}
 }
@@ -991,12 +990,12 @@ func (e *Engine) GetDisplayStatus(site models.Site) string {
 	if e.isInMaintenance(site.ID) {
 		return "MAINT"
 	}
-	return site.Status
+	return string(site.Status)
 }
 
 func (e *Engine) checkGroup(_ context.Context, site models.Site) {
 	e.mu.RLock()
-	status := "UP"
+	status := models.StatusUp
 	hasChildren := false
 	for _, child := range e.liveState {
 		if child.ParentID != site.ID || child.Type == "group" {
@@ -1006,20 +1005,20 @@ func (e *Engine) checkGroup(_ context.Context, site models.Site) {
 		if child.Paused || e.isInMaintenance(child.ID) {
 			continue
 		}
-		if child.Status == "DOWN" || child.Status == "SSL EXP" {
-			status = "DOWN"
-		} else if child.Status == "STALE" && status != "DOWN" {
-			status = "STALE"
-		} else if child.Status == "LATE" && status != "DOWN" && status != "STALE" {
-			status = "LATE"
-		} else if child.Status == "PENDING" && status != "DOWN" && status != "STALE" && status != "LATE" {
-			status = "PENDING"
+		if child.Status == models.StatusDown || child.Status == models.StatusSSLExp {
+			status = models.StatusDown
+		} else if child.Status == models.StatusStale && status != models.StatusDown {
+			status = models.StatusStale
+		} else if child.Status == models.StatusLate && status != models.StatusDown && status != models.StatusStale {
+			status = models.StatusLate
+		} else if child.Status == models.StatusPending && status != models.StatusDown && status != models.StatusStale && status != models.StatusLate {
+			status = models.StatusPending
 		}
 	}
 	e.mu.RUnlock()
 
 	if !hasChildren {
-		status = "PENDING"
+		status = models.StatusPending
 	}
 
 	e.applyState(site.ID, func(s *models.Site) {
@@ -1072,15 +1071,15 @@ func (e *Engine) IngestProbeResult(nodeID string, siteID int, latencyNs int64, i
 
 	aggUp, avgLatency := AggregateStatus(results, e.aggStrategy)
 
-	rawStatus := "UP"
+	probeStatus := models.StatusUp
 	if !aggUp {
-		rawStatus = "DOWN"
+		probeStatus = models.StatusDown
 	}
 
 	updatedSite := site
 	updatedSite.Latency = time.Duration(avgLatency)
 	updatedSite.LastCheck = time.Now()
-	e.handleStatusChange(updatedSite, rawStatus, 0, time.Duration(avgLatency), errorReason)
+	e.handleStatusChange(updatedSite, string(probeStatus), 0, time.Duration(avgLatency), errorReason)
 }
 
 func (e *Engine) GetProbeResults(siteID int) map[string]NodeResult {
diff --git a/internal/monitor/monitor_test.go b/internal/monitor/monitor_test.go
index 80c5936..28f4ae0 100644
--- a/internal/monitor/monitor_test.go
+++ b/internal/monitor/monitor_test.go
@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/store/storetest"
 )
 
 // --- Mock Store ---
@@ -19,6 +20,7 @@ type savedCheck struct {
 }
 
 type mockStore struct {
+	storetest.BaseMock
 	mu            sync.Mutex
 	sites         []models.Site
 	alerts        map[int]models.AlertConfig
@@ -38,42 +40,8 @@ func newMockStore() *mockStore {
 	}
 }
 
-func (m *mockStore) Init(context.Context) error                                        { return nil }
-func (m *mockStore) GetSites(context.Context) ([]models.Site, error)                   { return m.sites, nil }
-func (m *mockStore) AddSite(context.Context, models.Site) error                        { return nil }
-func (m *mockStore) UpdateSite(context.Context, models.Site) error                     { return nil }
-func (m *mockStore) UpdateSitePaused(context.Context, int, bool) error                 { return nil }
-func (m *mockStore) DeleteSite(context.Context, int) error                             { return nil }
-func (m *mockStore) AddAlert(context.Context, string, string, map[string]string) error { return nil }
-func (m *mockStore) UpdateAlert(context.Context, int, string, string, map[string]string) error {
-	return nil
-}
-func (m *mockStore) DeleteAlert(context.Context, int) error                        { return nil }
-func (m *mockStore) GetAllUsers(context.Context) ([]models.User, error)            { return nil, nil }
-func (m *mockStore) AddUser(context.Context, string, string, string) error         { return nil }
-func (m *mockStore) UpdateUser(context.Context, int, string, string, string) error { return nil }
-func (m *mockStore) DeleteUser(context.Context, int) error                         { return nil }
-func (m *mockStore) ExportData(context.Context) (models.Backup, error)             { return models.Backup{}, nil }
-func (m *mockStore) ImportData(context.Context, models.Backup) error               { return nil }
-func (m *mockStore) GetSiteByName(context.Context, string) (models.Site, error) {
-	return models.Site{}, nil
-}
-func (m *mockStore) AddSiteReturningID(context.Context, models.Site) (int, error) { return 0, nil }
-func (m *mockStore) AddAlertReturningID(context.Context, string, string, map[string]string) (int, error) {
-	return 0, nil
-}
-func (m *mockStore) SaveCheckFromNode(context.Context, int, string, int64, bool) error { return nil }
-func (m *mockStore) RegisterNode(context.Context, models.ProbeNode) error              { return nil }
-func (m *mockStore) GetNode(context.Context, string) (models.ProbeNode, error) {
-	return models.ProbeNode{}, nil
-}
-func (m *mockStore) GetAllNodes(context.Context) ([]models.ProbeNode, error) { return nil, nil }
-func (m *mockStore) UpdateNodeLastSeen(context.Context, string) error        { return nil }
-func (m *mockStore) DeleteNode(context.Context, string) error                { return nil }
-func (m *mockStore) LoadAlertHealth(context.Context) (map[int]models.AlertHealthRecord, error) {
-	return nil, nil
-}
-func (m *mockStore) SaveAlertHealth(context.Context, models.AlertHealthRecord) error { return nil }
+func (m *mockStore) GetSites(context.Context) ([]models.Site, error) { return m.sites, nil }
+
 func (m *mockStore) GetActiveMaintenanceWindows(context.Context) ([]models.MaintenanceWindow, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -83,25 +51,6 @@ func (m *mockStore) GetActiveMaintenanceWindows(context.Context) ([]models.Maint
 	}
 	return windows, nil
 }
-func (m *mockStore) GetAllMaintenanceWindows(context.Context, int) ([]models.MaintenanceWindow, error) {
-	return nil, nil
-}
-func (m *mockStore) AddMaintenanceWindow(context.Context, models.MaintenanceWindow) error { return nil }
-func (m *mockStore) EndMaintenanceWindow(context.Context, int) error                      { return nil }
-func (m *mockStore) DeleteMaintenanceWindow(context.Context, int) error                   { return nil }
-func (m *mockStore) PruneExpiredMaintenanceWindows(context.Context, time.Duration) (int64, error) {
-	return 0, nil
-}
-func (m *mockStore) GetPreference(context.Context, string) (string, error)              { return "", nil }
-func (m *mockStore) SetPreference(context.Context, string, string) error                { return nil }
-func (m *mockStore) SaveStateChange(context.Context, int, string, string, string) error { return nil }
-func (m *mockStore) GetStateChanges(context.Context, int, int) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) GetStateChangesSince(context.Context, int, time.Time) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) Close() error { return nil }
 
 func (m *mockStore) GetAllAlerts(context.Context) ([]models.AlertConfig, error) {
 	m.mu.Lock()
@@ -154,18 +103,14 @@ func (m *mockStore) SaveLog(_ context.Context, msg string) error {
 	return nil
 }
 
-func (m *mockStore) LoadLogs(_ context.Context, limit int) ([]string, error) {
+func (m *mockStore) LoadLogs(_ context.Context, _ int) ([]string, error) {
 	return m.logs, nil
 }
 
-func (m *mockStore) LoadAllHistory(_ context.Context, limit int) (map[int][]models.CheckRecord, error) {
+func (m *mockStore) LoadAllHistory(_ context.Context, _ int) (map[int][]models.CheckRecord, error) {
 	return m.history, nil
 }
 
-func (m *mockStore) PruneLogs(context.Context) error         { return nil }
-func (m *mockStore) PruneCheckHistory(context.Context) error { return nil }
-func (m *mockStore) PruneStateChanges(context.Context) error { return nil }
-
 // --- Helpers ---
 
 func newTestEngine(ms *mockStore) *Engine {
diff --git a/internal/monitor/sla.go b/internal/monitor/sla.go
index 90656cf..cfa815a 100644
--- a/internal/monitor/sla.go
+++ b/internal/monitor/sla.go
@@ -16,14 +16,14 @@ type SLAReport struct {
 	MTBF        time.Duration
 }
 
-func ComputeSLA(changes []models.StateChange, currentStatus string, window time.Duration) SLAReport {
+func ComputeSLA(changes []models.StateChange, currentStatus models.Status, window time.Duration) SLAReport {
 	now := time.Now()
 	windowStart := now.Add(-window)
 
 	report := SLAReport{Window: window}
 
 	if len(changes) == 0 {
-		if isDown(currentStatus) {
+		if models.Status(currentStatus).IsBroken() {
 			report.UptimePct = 0
 			report.Downtime = window
 		} else {
@@ -40,7 +40,7 @@ func ComputeSLA(changes []models.StateChange, currentStatus string, window time.
 	}
 
 	// Determine status at window start: last transition before or at windowStart.
-	statusAtStart := "UP"
+	statusAtStart := string(models.StatusUp)
 	for i := len(sorted) - 1; i >= 0; i-- {
 		if !sorted[i].ChangedAt.After(windowStart) {
 			statusAtStart = sorted[i].ToStatus
@@ -51,7 +51,7 @@ func ComputeSLA(changes []models.StateChange, currentStatus string, window time.
 	var upTime, downTime time.Duration
 	var outages []time.Duration
 	cursor := windowStart
-	wasDown := isDown(statusAtStart)
+	wasDown := models.Status(statusAtStart).IsBroken()
 
 	if wasDown {
 		report.OutageCount = 1
@@ -77,7 +77,7 @@ func ComputeSLA(changes []models.StateChange, currentStatus string, window time.
 			upTime += seg
 		}
 
-		newDown := isDown(sc.ToStatus)
+		newDown := models.Status(sc.ToStatus).IsBroken()
 		if !wasDown && newDown {
 			report.OutageCount++
 			outageStart = sc.ChangedAt
@@ -127,7 +127,7 @@ func ComputeSLA(changes []models.StateChange, currentStatus string, window time.
 	return report
 }
 
-func ComputeDailyBreakdown(changes []models.StateChange, currentStatus string, days int, now time.Time) []DayReport {
+func ComputeDailyBreakdown(changes []models.StateChange, currentStatus models.Status, days int, now time.Time) []DayReport {
 	reports := make([]DayReport, days)
 
 	for i := 0; i < days; i++ {
@@ -159,10 +159,6 @@ type DayReport struct {
 	UptimePct float64
 }
 
-func isDown(status string) bool {
-	return status == "DOWN" || status == "SSL EXP"
-}
-
 func filterChangesForWindow(changes []models.StateChange, start, end time.Time) []models.StateChange {
 	var filtered []models.StateChange
 	for _, sc := range changes {
@@ -180,7 +176,7 @@ func inferStatusAt(changes []models.StateChange, at time.Time) string {
 			return sc.ToStatus
 		}
 	}
-	return "UP"
+	return string(models.StatusUp)
 }
 
 func computeSLAForWindow(changes []models.StateChange, statusAtStart string, start, end time.Time) float64 {
@@ -193,7 +189,7 @@ func computeSLAForWindow(changes []models.StateChange, statusAtStart string, sta
 
 	var upTime, downTime time.Duration
 	cursor := start
-	wasDown := isDown(statusAtStart)
+	wasDown := models.Status(statusAtStart).IsBroken()
 
 	for _, sc := range sorted {
 		if sc.ChangedAt.Before(start) || !sc.ChangedAt.Before(end) {
@@ -205,7 +201,7 @@ func computeSLAForWindow(changes []models.StateChange, statusAtStart string, sta
 		} else {
 			upTime += seg
 		}
-		wasDown = isDown(sc.ToStatus)
+		wasDown = models.Status(sc.ToStatus).IsBroken()
 		cursor = sc.ChangedAt
 	}
 
diff --git a/internal/monitor/sla_test.go b/internal/monitor/sla_test.go
index 474971a..5edfe11 100644
--- a/internal/monitor/sla_test.go
+++ b/internal/monitor/sla_test.go
@@ -137,24 +137,24 @@ func TestComputeDailyBreakdown(t *testing.T) {
 	}
 }
 
-func TestIsDown(t *testing.T) {
-	if !isDown("DOWN") {
-		t.Error("DOWN should be down")
+func TestIsBroken(t *testing.T) {
+	if !models.StatusDown.IsBroken() {
+		t.Error("DOWN should be broken")
 	}
-	if !isDown("SSL EXP") {
-		t.Error("SSL EXP should be down")
+	if !models.StatusSSLExp.IsBroken() {
+		t.Error("SSL EXP should be broken")
 	}
-	if isDown("UP") {
-		t.Error("UP should not be down")
+	if models.StatusUp.IsBroken() {
+		t.Error("UP should not be broken")
 	}
-	if isDown("LATE") {
-		t.Error("LATE should not be down")
+	if models.StatusLate.IsBroken() {
+		t.Error("LATE should not be broken")
 	}
-	if isDown("STALE") {
-		t.Error("STALE should not be down")
+	if models.StatusStale.IsBroken() {
+		t.Error("STALE should not be broken")
 	}
-	if isDown("PENDING") {
-		t.Error("PENDING should not be down")
+	if models.StatusPending.IsBroken() {
+		t.Error("PENDING should not be broken")
 	}
 }
 
diff --git a/internal/server/server.go b/internal/server/server.go
index 6538e41..c8c3414 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -468,15 +468,15 @@ func Start(cfg ServerConfig, s store.Store, eng *monitor.Engine) *http.Server {
 			}
 			public := make(map[int]statusSite, len(state))
 			for id, site := range state {
-				status := site.Status
+				displayStatus := string(site.Status)
 				if allInMaint || maintSet[site.ID] || (site.ParentID > 0 && maintSet[site.ParentID]) {
-					status = "MAINT"
+					displayStatus = "MAINT"
 				}
 				public[id] = statusSite{
 					Name:      site.Name,
 					Type:      site.Type,
 					URL:       site.URL,
-					Status:    status,
+					Status:    displayStatus,
 					Paused:    site.Paused,
 					LastCheck: site.LastCheck,
 					Latency:   site.Latency,
@@ -569,10 +569,10 @@ func renderStatusPage(w http.ResponseWriter, title string, eng *monitor.Engine)
 
 	sort.Slice(sites, func(i, j int) bool {
 		if sites[i].Status != sites[j].Status {
-			if sites[i].Status == "DOWN" {
+			if sites[i].Status == models.StatusDown {
 				return true
 			}
-			if sites[j].Status == "DOWN" {
+			if sites[j].Status == models.StatusDown {
 				return false
 			}
 		}
diff --git a/internal/server/server_test.go b/internal/server/server_test.go
index ad14ef9..77eb81e 100644
--- a/internal/server/server_test.go
+++ b/internal/server/server_test.go
@@ -13,11 +13,13 @@ import (
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/monitor"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/store/storetest"
 )
 
 // --- Mock Store ---
 
 type mockStore struct {
+	storetest.BaseMock
 	mu              sync.Mutex
 	sites           []models.Site
 	alerts          []models.AlertConfig
@@ -33,84 +35,10 @@ func newMockStore() *mockStore {
 	}
 }
 
-func (m *mockStore) Init(_ context.Context) error                            { return nil }
-func (m *mockStore) GetSites(_ context.Context) ([]models.Site, error)       { return m.sites, nil }
-func (m *mockStore) AddSite(_ context.Context, _ models.Site) error          { return nil }
-func (m *mockStore) UpdateSite(_ context.Context, _ models.Site) error       { return nil }
-func (m *mockStore) UpdateSitePaused(_ context.Context, _ int, _ bool) error { return nil }
-func (m *mockStore) DeleteSite(_ context.Context, _ int) error               { return nil }
+func (m *mockStore) GetSites(_ context.Context) ([]models.Site, error) { return m.sites, nil }
 func (m *mockStore) GetAllAlerts(_ context.Context) ([]models.AlertConfig, error) {
 	return m.alerts, nil
 }
-func (m *mockStore) GetAlert(_ context.Context, _ int) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
-}
-func (m *mockStore) AddAlert(_ context.Context, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *mockStore) UpdateAlert(_ context.Context, _ int, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *mockStore) DeleteAlert(_ context.Context, _ int) error                    { return nil }
-func (m *mockStore) GetAllUsers(_ context.Context) ([]models.User, error)          { return nil, nil }
-func (m *mockStore) AddUser(_ context.Context, _ string, _ string, _ string) error { return nil }
-func (m *mockStore) UpdateUser(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *mockStore) DeleteUser(_ context.Context, _ int) error                 { return nil }
-func (m *mockStore) SaveCheck(_ context.Context, _ int, _ int64, _ bool) error { return nil }
-func (m *mockStore) SaveCheckFromNode(_ context.Context, siteID int, nodeID string, latencyNs int64, isUp bool) error {
-	return nil
-}
-func (m *mockStore) LoadAllHistory(_ context.Context, _ int) (map[int][]models.CheckRecord, error) {
-	return nil, nil
-}
-func (m *mockStore) GetSiteByName(_ context.Context, _ string) (models.Site, error) {
-	return models.Site{}, nil
-}
-func (m *mockStore) GetAlertByName(_ context.Context, _ string) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
-}
-func (m *mockStore) AddSiteReturningID(_ context.Context, _ models.Site) (int, error) { return 0, nil }
-func (m *mockStore) AddAlertReturningID(_ context.Context, _ string, _ string, _ map[string]string) (int, error) {
-	return 0, nil
-}
-func (m *mockStore) GetAllNodes(_ context.Context) ([]models.ProbeNode, error) { return nil, nil }
-func (m *mockStore) UpdateNodeLastSeen(_ context.Context, _ string) error      { return nil }
-func (m *mockStore) DeleteNode(_ context.Context, _ string) error              { return nil }
-func (m *mockStore) LoadAlertHealth(_ context.Context) (map[int]models.AlertHealthRecord, error) {
-	return nil, nil
-}
-func (m *mockStore) SaveAlertHealth(_ context.Context, _ models.AlertHealthRecord) error { return nil }
-func (m *mockStore) SaveLog(_ context.Context, _ string) error                           { return nil }
-func (m *mockStore) PruneLogs(_ context.Context) error                                   { return nil }
-func (m *mockStore) PruneCheckHistory(_ context.Context) error                           { return nil }
-func (m *mockStore) PruneStateChanges(_ context.Context) error                           { return nil }
-func (m *mockStore) LoadLogs(_ context.Context, _ int) ([]string, error)                 { return nil, nil }
-func (m *mockStore) GetAllMaintenanceWindows(_ context.Context, _ int) ([]models.MaintenanceWindow, error) {
-	return nil, nil
-}
-func (m *mockStore) AddMaintenanceWindow(_ context.Context, _ models.MaintenanceWindow) error {
-	return nil
-}
-func (m *mockStore) EndMaintenanceWindow(_ context.Context, _ int) error    { return nil }
-func (m *mockStore) DeleteMaintenanceWindow(_ context.Context, _ int) error { return nil }
-func (m *mockStore) PruneExpiredMaintenanceWindows(_ context.Context, _ time.Duration) (int64, error) {
-	return 0, nil
-}
-func (m *mockStore) IsMonitorInMaintenance(_ context.Context, _ int) (bool, error) { return false, nil }
-func (m *mockStore) GetPreference(_ context.Context, _ string) (string, error)     { return "", nil }
-func (m *mockStore) SetPreference(_ context.Context, _ string, _ string) error     { return nil }
-func (m *mockStore) SaveStateChange(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *mockStore) GetStateChanges(_ context.Context, _ int, _ int) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) GetStateChangesSince(_ context.Context, _ int, _ time.Time) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *mockStore) Close() error { return nil }
 
 func (m *mockStore) ExportData(_ context.Context) (models.Backup, error) {
 	return models.Backup{
diff --git a/internal/store/dialect.go b/internal/store/dialect.go
index 2e9ce2c..81aa157 100644
--- a/internal/store/dialect.go
+++ b/internal/store/dialect.go
@@ -5,10 +5,16 @@ import (
 	"strconv"
 )
 
+type Migration struct {
+	Version int
+	SQL     string
+}
+
 type Dialect interface {
 	DriverName() string
 	CreateTablesSQL() []string
-	MigrationsSQL() []string
+	Migrations() []Migration
+	BaselineVersion() int
 	BoolFalse() string
 	ResetSequenceOnEmpty(db *sql.DB, table string)
 	ImportWipe(tx *sql.Tx)
diff --git a/internal/store/postgres.go b/internal/store/postgres.go
index 1be31ca..00511dd 100644
--- a/internal/store/postgres.go
+++ b/internal/store/postgres.go
@@ -13,8 +13,9 @@ func NewPostgresStore(connStr string) (*SQLStore, error) {
 	return NewSQLStore("postgres", connStr, &PostgresDialect{})
 }
 
-func (d *PostgresDialect) DriverName() string { return "postgres" }
-func (d *PostgresDialect) BoolFalse() string  { return "FALSE" }
+func (d *PostgresDialect) DriverName() string   { return "postgres" }
+func (d *PostgresDialect) BoolFalse() string    { return "FALSE" }
+func (d *PostgresDialect) BaselineVersion() int { return 21 }
 
 func (d *PostgresDialect) CreateTablesSQL() []string {
 	return []string{
@@ -32,7 +33,8 @@ func (d *PostgresDialect) CreateTablesSQL() []string {
 			method TEXT DEFAULT 'GET', description TEXT DEFAULT '',
 			parent_id INTEGER DEFAULT 0, accepted_codes TEXT DEFAULT '200-299',
 			dns_resolve_type TEXT DEFAULT '', dns_server TEXT DEFAULT '',
-			ignore_tls BOOLEAN DEFAULT FALSE, paused BOOLEAN DEFAULT FALSE
+			ignore_tls BOOLEAN DEFAULT FALSE, paused BOOLEAN DEFAULT FALSE,
+			regions TEXT DEFAULT ''
 		)`,
 		`CREATE TABLE IF NOT EXISTS users (
 			id SERIAL PRIMARY KEY,
@@ -42,7 +44,8 @@ func (d *PostgresDialect) CreateTablesSQL() []string {
 		`CREATE TABLE IF NOT EXISTS check_history (
 			id SERIAL PRIMARY KEY,
 			site_id INTEGER NOT NULL, latency_ns BIGINT,
-			is_up BOOLEAN, checked_at TIMESTAMPTZ DEFAULT NOW()
+			is_up BOOLEAN, checked_at TIMESTAMPTZ DEFAULT NOW(),
+			node_id TEXT DEFAULT ''
 		)`,
 		`CREATE INDEX IF NOT EXISTS idx_check_history_site ON check_history(site_id, checked_at DESC)`,
 		`CREATE TABLE IF NOT EXISTS nodes (
@@ -92,29 +95,29 @@ func (d *PostgresDialect) CreateTablesSQL() []string {
 	}
 }
 
-func (d *PostgresDialect) MigrationsSQL() []string {
-	return []string{
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS hostname TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS port INTEGER DEFAULT 0",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS timeout INTEGER DEFAULT 0",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS method TEXT DEFAULT 'GET'",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS description TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS parent_id INTEGER DEFAULT 0",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS accepted_codes TEXT DEFAULT '200-299'",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS dns_resolve_type TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS dns_server TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS ignore_tls BOOLEAN DEFAULT FALSE",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS paused BOOLEAN DEFAULT FALSE",
-		"ALTER TABLE check_history ADD COLUMN IF NOT EXISTS node_id TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS regions TEXT DEFAULT ''",
-		"ALTER TABLE check_history ALTER COLUMN checked_at TYPE TIMESTAMPTZ USING checked_at AT TIME ZONE 'UTC'",
-		"ALTER TABLE nodes ALTER COLUMN last_seen TYPE TIMESTAMPTZ USING last_seen AT TIME ZONE 'UTC'",
-		"ALTER TABLE logs ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC'",
-		"ALTER TABLE maintenance_windows ALTER COLUMN start_time TYPE TIMESTAMPTZ USING start_time AT TIME ZONE 'UTC'",
-		"ALTER TABLE maintenance_windows ALTER COLUMN end_time TYPE TIMESTAMPTZ USING end_time AT TIME ZONE 'UTC'",
-		"ALTER TABLE maintenance_windows ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC'",
-		"ALTER TABLE state_changes ALTER COLUMN changed_at TYPE TIMESTAMPTZ USING changed_at AT TIME ZONE 'UTC'",
-		"ALTER TABLE alert_health ALTER COLUMN last_send_at TYPE TIMESTAMPTZ USING last_send_at AT TIME ZONE 'UTC'",
+func (d *PostgresDialect) Migrations() []Migration {
+	return []Migration{
+		{1, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS hostname TEXT DEFAULT ''"},
+		{2, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS port INTEGER DEFAULT 0"},
+		{3, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS timeout INTEGER DEFAULT 0"},
+		{4, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS method TEXT DEFAULT 'GET'"},
+		{5, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS description TEXT DEFAULT ''"},
+		{6, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS parent_id INTEGER DEFAULT 0"},
+		{7, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS accepted_codes TEXT DEFAULT '200-299'"},
+		{8, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS dns_resolve_type TEXT DEFAULT ''"},
+		{9, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS dns_server TEXT DEFAULT ''"},
+		{10, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS ignore_tls BOOLEAN DEFAULT FALSE"},
+		{11, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS paused BOOLEAN DEFAULT FALSE"},
+		{12, "ALTER TABLE check_history ADD COLUMN IF NOT EXISTS node_id TEXT DEFAULT ''"},
+		{13, "ALTER TABLE sites ADD COLUMN IF NOT EXISTS regions TEXT DEFAULT ''"},
+		{14, "ALTER TABLE check_history ALTER COLUMN checked_at TYPE TIMESTAMPTZ USING checked_at AT TIME ZONE 'UTC'"},
+		{15, "ALTER TABLE nodes ALTER COLUMN last_seen TYPE TIMESTAMPTZ USING last_seen AT TIME ZONE 'UTC'"},
+		{16, "ALTER TABLE logs ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC'"},
+		{17, "ALTER TABLE maintenance_windows ALTER COLUMN start_time TYPE TIMESTAMPTZ USING start_time AT TIME ZONE 'UTC'"},
+		{18, "ALTER TABLE maintenance_windows ALTER COLUMN end_time TYPE TIMESTAMPTZ USING end_time AT TIME ZONE 'UTC'"},
+		{19, "ALTER TABLE maintenance_windows ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC'"},
+		{20, "ALTER TABLE state_changes ALTER COLUMN changed_at TYPE TIMESTAMPTZ USING changed_at AT TIME ZONE 'UTC'"},
+		{21, "ALTER TABLE alert_health ALTER COLUMN last_send_at TYPE TIMESTAMPTZ USING last_send_at AT TIME ZONE 'UTC'"},
 	}
 }
 
diff --git a/internal/store/sqlite.go b/internal/store/sqlite.go
index ca294e5..53b1489 100644
--- a/internal/store/sqlite.go
+++ b/internal/store/sqlite.go
@@ -28,8 +28,9 @@ func NewSQLiteStore(path string) (*SQLStore, error) {
 	return s, nil
 }
 
-func (d *SQLiteDialect) DriverName() string { return "sqlite" }
-func (d *SQLiteDialect) BoolFalse() string  { return "0" }
+func (d *SQLiteDialect) DriverName() string   { return "sqlite" }
+func (d *SQLiteDialect) BoolFalse() string    { return "0" }
+func (d *SQLiteDialect) BaselineVersion() int { return 13 }
 
 func (d *SQLiteDialect) CreateTablesSQL() []string {
 	return []string{
@@ -47,7 +48,8 @@ func (d *SQLiteDialect) CreateTablesSQL() []string {
 			method TEXT DEFAULT 'GET', description TEXT DEFAULT '',
 			parent_id INTEGER DEFAULT 0, accepted_codes TEXT DEFAULT '200-299',
 			dns_resolve_type TEXT DEFAULT '', dns_server TEXT DEFAULT '',
-			ignore_tls BOOLEAN DEFAULT 0, paused BOOLEAN DEFAULT 0
+			ignore_tls BOOLEAN DEFAULT 0, paused BOOLEAN DEFAULT 0,
+			regions TEXT DEFAULT ''
 		)`,
 		`CREATE TABLE IF NOT EXISTS users (
 			id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -57,7 +59,8 @@ func (d *SQLiteDialect) CreateTablesSQL() []string {
 		`CREATE TABLE IF NOT EXISTS check_history (
 			id INTEGER PRIMARY KEY AUTOINCREMENT,
 			site_id INTEGER NOT NULL, latency_ns INTEGER,
-			is_up BOOLEAN, checked_at DATETIME DEFAULT CURRENT_TIMESTAMP
+			is_up BOOLEAN, checked_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+			node_id TEXT DEFAULT ''
 		)`,
 		`CREATE INDEX IF NOT EXISTS idx_check_history_site ON check_history(site_id, checked_at DESC)`,
 		`CREATE TABLE IF NOT EXISTS nodes (
@@ -107,21 +110,21 @@ func (d *SQLiteDialect) CreateTablesSQL() []string {
 	}
 }
 
-func (d *SQLiteDialect) MigrationsSQL() []string {
-	return []string{
-		"ALTER TABLE sites ADD COLUMN hostname TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN port INTEGER DEFAULT 0",
-		"ALTER TABLE sites ADD COLUMN timeout INTEGER DEFAULT 0",
-		"ALTER TABLE sites ADD COLUMN method TEXT DEFAULT 'GET'",
-		"ALTER TABLE sites ADD COLUMN description TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN parent_id INTEGER DEFAULT 0",
-		"ALTER TABLE sites ADD COLUMN accepted_codes TEXT DEFAULT '200-299'",
-		"ALTER TABLE sites ADD COLUMN dns_resolve_type TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN dns_server TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN ignore_tls BOOLEAN DEFAULT 0",
-		"ALTER TABLE sites ADD COLUMN paused BOOLEAN DEFAULT 0",
-		"ALTER TABLE check_history ADD COLUMN node_id TEXT DEFAULT ''",
-		"ALTER TABLE sites ADD COLUMN regions TEXT DEFAULT ''",
+func (d *SQLiteDialect) Migrations() []Migration {
+	return []Migration{
+		{1, "ALTER TABLE sites ADD COLUMN hostname TEXT DEFAULT ''"},
+		{2, "ALTER TABLE sites ADD COLUMN port INTEGER DEFAULT 0"},
+		{3, "ALTER TABLE sites ADD COLUMN timeout INTEGER DEFAULT 0"},
+		{4, "ALTER TABLE sites ADD COLUMN method TEXT DEFAULT 'GET'"},
+		{5, "ALTER TABLE sites ADD COLUMN description TEXT DEFAULT ''"},
+		{6, "ALTER TABLE sites ADD COLUMN parent_id INTEGER DEFAULT 0"},
+		{7, "ALTER TABLE sites ADD COLUMN accepted_codes TEXT DEFAULT '200-299'"},
+		{8, "ALTER TABLE sites ADD COLUMN dns_resolve_type TEXT DEFAULT ''"},
+		{9, "ALTER TABLE sites ADD COLUMN dns_server TEXT DEFAULT ''"},
+		{10, "ALTER TABLE sites ADD COLUMN ignore_tls BOOLEAN DEFAULT 0"},
+		{11, "ALTER TABLE sites ADD COLUMN paused BOOLEAN DEFAULT 0"},
+		{12, "ALTER TABLE check_history ADD COLUMN node_id TEXT DEFAULT ''"},
+		{13, "ALTER TABLE sites ADD COLUMN regions TEXT DEFAULT ''"},
 	}
 }
 
diff --git a/internal/store/sqlstore.go b/internal/store/sqlstore.go
index 05eff31..5821225 100644
--- a/internal/store/sqlstore.go
+++ b/internal/store/sqlstore.go
@@ -7,7 +7,6 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
-	"strings"
 	"time"
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
@@ -80,13 +79,34 @@ func (s *SQLStore) Init(ctx context.Context) error {
 			return err
 		}
 	}
-	for _, m := range s.dialect.MigrationsSQL() {
-		if _, err := s.db.ExecContext(ctx, m); err != nil {
-			errMsg := err.Error()
-			if strings.Contains(errMsg, "already exists") || strings.Contains(errMsg, "duplicate column") {
-				continue
-			}
-			return fmt.Errorf("migration failed: %w", err)
+
+	if _, err := s.db.ExecContext(ctx, `CREATE TABLE IF NOT EXISTS schema_version (
+		version INTEGER PRIMARY KEY,
+		applied_at DATETIME DEFAULT CURRENT_TIMESTAMP
+	)`); err != nil {
+		return fmt.Errorf("create schema_version: %w", err)
+	}
+
+	var current int
+	_ = s.db.QueryRowContext(ctx, "SELECT COALESCE(MAX(version), 0) FROM schema_version").Scan(&current) //nolint:errcheck
+
+	if current == 0 {
+		baseline := s.dialect.BaselineVersion()
+		if _, err := s.db.ExecContext(ctx, s.q("INSERT INTO schema_version (version) VALUES (?)"), baseline); err != nil {
+			return fmt.Errorf("seed baseline version: %w", err)
+		}
+		current = baseline
+	}
+
+	for _, m := range s.dialect.Migrations() {
+		if m.Version <= current {
+			continue
+		}
+		if _, err := s.db.ExecContext(ctx, m.SQL); err != nil {
+			return fmt.Errorf("migration %d failed: %w", m.Version, err)
+		}
+		if _, err := s.db.ExecContext(ctx, s.q("INSERT INTO schema_version (version) VALUES (?)"), m.Version); err != nil {
+			return fmt.Errorf("record migration %d: %w", m.Version, err)
 		}
 	}
 	return nil
@@ -325,8 +345,10 @@ func (s *SQLStore) UpdateAlert(ctx context.Context, id int, name, aType string,
 }
 
 func (s *SQLStore) DeleteAlert(ctx context.Context, id int) error {
-	_, err := s.db.ExecContext(ctx, s.q("DELETE FROM alerts WHERE id=?"), id)
-	if err != nil {
+	if _, err := s.db.ExecContext(ctx, s.q("UPDATE sites SET alert_id = 0 WHERE alert_id = ?"), id); err != nil {
+		return err
+	}
+	if _, err := s.db.ExecContext(ctx, s.q("DELETE FROM alerts WHERE id=?"), id); err != nil {
 		return err
 	}
 	s.dialect.ResetSequenceOnEmpty(s.db, "alerts")
diff --git a/internal/store/storetest/mock.go b/internal/store/storetest/mock.go
new file mode 100644
index 0000000..d8686f9
--- /dev/null
+++ b/internal/store/storetest/mock.go
@@ -0,0 +1,274 @@
+package storetest
+
+import (
+	"context"
+	"time"
+
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
+)
+
+// BaseMock implements store.Store with no-op defaults. Embed it in test-specific
+// mocks and override only the methods you need via the exported Func fields or
+// by shadowing the method on the embedding struct.
+type BaseMock struct {
+	GetSitesFunc                    func(ctx context.Context) ([]models.Site, error)
+	AddSiteFunc                     func(ctx context.Context, site models.Site) error
+	UpdateSiteFunc                  func(ctx context.Context, site models.Site) error
+	GetAllAlertsFunc                func(ctx context.Context) ([]models.AlertConfig, error)
+	GetAlertFunc                    func(ctx context.Context, id int) (models.AlertConfig, error)
+	GetAllUsersFunc                 func(ctx context.Context) ([]models.User, error)
+	GetAllNodesFunc                 func(ctx context.Context) ([]models.ProbeNode, error)
+	GetActiveMaintenanceWindowsFunc func(ctx context.Context) ([]models.MaintenanceWindow, error)
+	GetAllMaintenanceWindowsFunc    func(ctx context.Context, limit int) ([]models.MaintenanceWindow, error)
+	IsMonitorInMaintenanceFunc      func(ctx context.Context, id int) (bool, error)
+	LoadAlertHealthFunc             func(ctx context.Context) (map[int]models.AlertHealthRecord, error)
+	LoadAllHistoryFunc              func(ctx context.Context, limit int) (map[int][]models.CheckRecord, error)
+	SaveCheckFunc                   func(ctx context.Context, siteID int, latencyNs int64, isUp bool) error
+	SaveCheckFromNodeFunc           func(ctx context.Context, siteID int, nodeID string, latencyNs int64, isUp bool) error
+	SaveLogFunc                     func(ctx context.Context, message string) error
+	SaveStateChangeFunc             func(ctx context.Context, siteID int, from, to, reason string) error
+	SaveAlertHealthFunc             func(ctx context.Context, h models.AlertHealthRecord) error
+	GetStateChangesFunc             func(ctx context.Context, siteID, limit int) ([]models.StateChange, error)
+	GetStateChangesSinceFunc        func(ctx context.Context, siteID int, since time.Time) ([]models.StateChange, error)
+	ExportDataFunc                  func(ctx context.Context) (models.Backup, error)
+	ImportDataFunc                  func(ctx context.Context, data models.Backup) error
+	RegisterNodeFunc                func(ctx context.Context, node models.ProbeNode) error
+	GetNodeFunc                     func(ctx context.Context, id string) (models.ProbeNode, error)
+	GetPreferenceFunc               func(ctx context.Context, key string) (string, error)
+	SetPreferenceFunc               func(ctx context.Context, key, value string) error
+}
+
+func (m *BaseMock) Init(_ context.Context) error { return nil }
+func (m *BaseMock) Close() error                 { return nil }
+
+func (m *BaseMock) GetSites(ctx context.Context) ([]models.Site, error) {
+	if m.GetSitesFunc != nil {
+		return m.GetSitesFunc(ctx)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) AddSite(ctx context.Context, site models.Site) error {
+	if m.AddSiteFunc != nil {
+		return m.AddSiteFunc(ctx, site)
+	}
+	return nil
+}
+
+func (m *BaseMock) UpdateSite(ctx context.Context, site models.Site) error {
+	if m.UpdateSiteFunc != nil {
+		return m.UpdateSiteFunc(ctx, site)
+	}
+	return nil
+}
+
+func (m *BaseMock) UpdateSitePaused(_ context.Context, _ int, _ bool) error { return nil }
+
+func (m *BaseMock) DeleteSite(_ context.Context, _ int) error { return nil }
+
+func (m *BaseMock) GetAllAlerts(ctx context.Context) ([]models.AlertConfig, error) {
+	if m.GetAllAlertsFunc != nil {
+		return m.GetAllAlertsFunc(ctx)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) GetAlert(ctx context.Context, id int) (models.AlertConfig, error) {
+	if m.GetAlertFunc != nil {
+		return m.GetAlertFunc(ctx, id)
+	}
+	return models.AlertConfig{}, nil
+}
+
+func (m *BaseMock) AddAlert(_ context.Context, _ string, _ string, _ map[string]string) error {
+	return nil
+}
+
+func (m *BaseMock) UpdateAlert(_ context.Context, _ int, _ string, _ string, _ map[string]string) error {
+	return nil
+}
+
+func (m *BaseMock) DeleteAlert(_ context.Context, _ int) error { return nil }
+
+func (m *BaseMock) GetSiteByName(_ context.Context, _ string) (models.Site, error) {
+	return models.Site{}, nil
+}
+
+func (m *BaseMock) GetAlertByName(_ context.Context, _ string) (models.AlertConfig, error) {
+	return models.AlertConfig{}, nil
+}
+
+func (m *BaseMock) AddSiteReturningID(_ context.Context, _ models.Site) (int, error) { return 0, nil }
+
+func (m *BaseMock) AddAlertReturningID(_ context.Context, _ string, _ string, _ map[string]string) (int, error) {
+	return 0, nil
+}
+
+func (m *BaseMock) GetAllUsers(ctx context.Context) ([]models.User, error) {
+	if m.GetAllUsersFunc != nil {
+		return m.GetAllUsersFunc(ctx)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) AddUser(_ context.Context, _ string, _ string, _ string) error { return nil }
+
+func (m *BaseMock) UpdateUser(_ context.Context, _ int, _ string, _ string, _ string) error {
+	return nil
+}
+
+func (m *BaseMock) DeleteUser(_ context.Context, _ int) error { return nil }
+
+func (m *BaseMock) SaveCheck(ctx context.Context, siteID int, latencyNs int64, isUp bool) error {
+	if m.SaveCheckFunc != nil {
+		return m.SaveCheckFunc(ctx, siteID, latencyNs, isUp)
+	}
+	return nil
+}
+
+func (m *BaseMock) SaveCheckFromNode(ctx context.Context, siteID int, nodeID string, latencyNs int64, isUp bool) error {
+	if m.SaveCheckFromNodeFunc != nil {
+		return m.SaveCheckFromNodeFunc(ctx, siteID, nodeID, latencyNs, isUp)
+	}
+	return nil
+}
+
+func (m *BaseMock) LoadAllHistory(ctx context.Context, limit int) (map[int][]models.CheckRecord, error) {
+	if m.LoadAllHistoryFunc != nil {
+		return m.LoadAllHistoryFunc(ctx, limit)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) PruneCheckHistory(_ context.Context) error { return nil }
+
+func (m *BaseMock) SaveStateChange(ctx context.Context, siteID int, from, to, reason string) error {
+	if m.SaveStateChangeFunc != nil {
+		return m.SaveStateChangeFunc(ctx, siteID, from, to, reason)
+	}
+	return nil
+}
+
+func (m *BaseMock) GetStateChanges(ctx context.Context, siteID, limit int) ([]models.StateChange, error) {
+	if m.GetStateChangesFunc != nil {
+		return m.GetStateChangesFunc(ctx, siteID, limit)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) GetStateChangesSince(ctx context.Context, siteID int, since time.Time) ([]models.StateChange, error) {
+	if m.GetStateChangesSinceFunc != nil {
+		return m.GetStateChangesSinceFunc(ctx, siteID, since)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) PruneStateChanges(_ context.Context) error { return nil }
+
+func (m *BaseMock) RegisterNode(ctx context.Context, node models.ProbeNode) error {
+	if m.RegisterNodeFunc != nil {
+		return m.RegisterNodeFunc(ctx, node)
+	}
+	return nil
+}
+
+func (m *BaseMock) GetNode(ctx context.Context, id string) (models.ProbeNode, error) {
+	if m.GetNodeFunc != nil {
+		return m.GetNodeFunc(ctx, id)
+	}
+	return models.ProbeNode{}, nil
+}
+
+func (m *BaseMock) GetAllNodes(ctx context.Context) ([]models.ProbeNode, error) {
+	if m.GetAllNodesFunc != nil {
+		return m.GetAllNodesFunc(ctx)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) UpdateNodeLastSeen(_ context.Context, _ string) error { return nil }
+func (m *BaseMock) DeleteNode(_ context.Context, _ string) error         { return nil }
+
+func (m *BaseMock) LoadAlertHealth(ctx context.Context) (map[int]models.AlertHealthRecord, error) {
+	if m.LoadAlertHealthFunc != nil {
+		return m.LoadAlertHealthFunc(ctx)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) SaveAlertHealth(ctx context.Context, h models.AlertHealthRecord) error {
+	if m.SaveAlertHealthFunc != nil {
+		return m.SaveAlertHealthFunc(ctx, h)
+	}
+	return nil
+}
+
+func (m *BaseMock) SaveLog(ctx context.Context, message string) error {
+	if m.SaveLogFunc != nil {
+		return m.SaveLogFunc(ctx, message)
+	}
+	return nil
+}
+
+func (m *BaseMock) LoadLogs(_ context.Context, _ int) ([]string, error) { return nil, nil }
+func (m *BaseMock) PruneLogs(_ context.Context) error                   { return nil }
+
+func (m *BaseMock) GetActiveMaintenanceWindows(ctx context.Context) ([]models.MaintenanceWindow, error) {
+	if m.GetActiveMaintenanceWindowsFunc != nil {
+		return m.GetActiveMaintenanceWindowsFunc(ctx)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) GetAllMaintenanceWindows(ctx context.Context, limit int) ([]models.MaintenanceWindow, error) {
+	if m.GetAllMaintenanceWindowsFunc != nil {
+		return m.GetAllMaintenanceWindowsFunc(ctx, limit)
+	}
+	return nil, nil
+}
+
+func (m *BaseMock) AddMaintenanceWindow(_ context.Context, _ models.MaintenanceWindow) error {
+	return nil
+}
+
+func (m *BaseMock) EndMaintenanceWindow(_ context.Context, _ int) error    { return nil }
+func (m *BaseMock) DeleteMaintenanceWindow(_ context.Context, _ int) error { return nil }
+
+func (m *BaseMock) PruneExpiredMaintenanceWindows(_ context.Context, _ time.Duration) (int64, error) {
+	return 0, nil
+}
+
+func (m *BaseMock) IsMonitorInMaintenance(ctx context.Context, id int) (bool, error) {
+	if m.IsMonitorInMaintenanceFunc != nil {
+		return m.IsMonitorInMaintenanceFunc(ctx, id)
+	}
+	return false, nil
+}
+
+func (m *BaseMock) GetPreference(ctx context.Context, key string) (string, error) {
+	if m.GetPreferenceFunc != nil {
+		return m.GetPreferenceFunc(ctx, key)
+	}
+	return "", nil
+}
+
+func (m *BaseMock) SetPreference(ctx context.Context, key, value string) error {
+	if m.SetPreferenceFunc != nil {
+		return m.SetPreferenceFunc(ctx, key, value)
+	}
+	return nil
+}
+
+func (m *BaseMock) ExportData(ctx context.Context) (models.Backup, error) {
+	if m.ExportDataFunc != nil {
+		return m.ExportDataFunc(ctx)
+	}
+	return models.Backup{}, nil
+}
+
+func (m *BaseMock) ImportData(ctx context.Context, data models.Backup) error {
+	if m.ImportDataFunc != nil {
+		return m.ImportDataFunc(ctx, data)
+	}
+	return nil
+}
diff --git a/internal/tui/format.go b/internal/tui/format.go
index 660ba10..591371a 100644
--- a/internal/tui/format.go
+++ b/internal/tui/format.go
@@ -143,16 +143,16 @@ func (m Model) fmtRetries(site models.Site) string {
 		dispCount = site.MaxRetries
 	}
 	s := fmt.Sprintf("%d/%d", dispCount, site.MaxRetries)
-	if site.Status == "DOWN" {
+	if site.Status == models.StatusDown {
 		return m.st.dangerStyle.Render(s)
 	}
-	if site.Status == "UP" && site.FailureCount > 0 {
+	if site.Status == models.StatusUp && site.FailureCount > 0 {
 		return m.st.warnStyle.Render(s)
 	}
 	return s
 }
 
-func (m Model) fmtStatus(status string, paused bool, inMaint bool) string {
+func (m Model) fmtStatus(status models.Status, paused bool, inMaint bool) string {
 	if paused {
 		return m.st.warnStyle.Render("◇ PAUSED")
 	}
@@ -160,18 +160,18 @@ func (m Model) fmtStatus(status string, paused bool, inMaint bool) string {
 		return m.st.maintStyle.Render("◼ MAINT")
 	}
 	switch status {
-	case "DOWN":
+	case models.StatusDown:
 		return m.st.dangerStyle.Render("▼ DOWN")
-	case "SSL EXP":
+	case models.StatusSSLExp:
 		return m.st.dangerStyle.Render("▼ SSL EXP")
-	case "LATE":
+	case models.StatusLate:
 		return m.st.warnStyle.Render("◆ LATE")
-	case "STALE":
+	case models.StatusStale:
 		return m.st.staleStyle.Render("◆ STALE")
-	case "PENDING":
+	case models.StatusPending:
 		return m.st.subtleStyle.Render("○ PENDING")
 	default:
-		return m.st.specialStyle.Render("▲ " + status)
+		return m.st.specialStyle.Render("▲ " + string(status))
 	}
 }
 
diff --git a/internal/tui/format_test.go b/internal/tui/format_test.go
index 9ee8d36..7c02778 100644
--- a/internal/tui/format_test.go
+++ b/internal/tui/format_test.go
@@ -56,19 +56,19 @@ func TestSiteOrder(t *testing.T) {
 
 func TestFmtStatus(t *testing.T) {
 	tests := []struct {
-		status  string
+		status  models.Status
 		paused  bool
 		inMaint bool
 		wantSub string
 	}{
-		{"DOWN", false, false, "▼ DOWN"},
-		{"UP", false, false, "▲ UP"},
-		{"SSL EXP", false, false, "▼ SSL EXP"},
-		{"LATE", false, false, "◆ LATE"},
-		{"STALE", false, false, "◆ STALE"},
-		{"PENDING", false, false, "○ PENDING"},
-		{"DOWN", true, false, "◇ PAUSED"},
-		{"DOWN", false, true, "◼ MAINT"},
+		{models.StatusDown, false, false, "▼ DOWN"},
+		{models.StatusUp, false, false, "▲ UP"},
+		{models.StatusSSLExp, false, false, "▼ SSL EXP"},
+		{models.StatusLate, false, false, "◆ LATE"},
+		{models.StatusStale, false, false, "◆ STALE"},
+		{models.StatusPending, false, false, "○ PENDING"},
+		{models.StatusDown, true, false, "◇ PAUSED"},
+		{models.StatusDown, false, true, "◼ MAINT"},
 	}
 	for _, tt := range tests {
 		got := styledModel.fmtStatus(tt.status, tt.paused, tt.inMaint)
diff --git a/internal/tui/tab_sites.go b/internal/tui/tab_sites.go
index 6c970ee..c84a270 100644
--- a/internal/tui/tab_sites.go
+++ b/internal/tui/tab_sites.go
@@ -240,7 +240,7 @@ func (m Model) viewSitesTab() string {
 					name = limitStr(name, nameW-2)
 				}
 
-				if (site.Status == "DOWN" || site.Status == "SSL EXP" || site.Status == "LATE" || site.Status == "STALE") && site.LastError != "" {
+				if (site.Status == models.StatusDown || site.Status == models.StatusSSLExp || site.Status == models.StatusLate || site.Status == models.StatusStale) && site.LastError != "" {
 					nameLen := len([]rune(name))
 					errSpace := nameW - nameLen - 3
 					if errSpace > 10 {
diff --git a/internal/tui/update.go b/internal/tui/update.go
index b855a9f..63f019b 100644
--- a/internal/tui/update.go
+++ b/internal/tui/update.go
@@ -455,7 +455,7 @@ func (m *Model) handleSLAData(msg slaDataMsg) (tea.Model, tea.Cmd) {
 	}
 	period := slaPeriods[msg.periodIdx]
 
-	var currentStatus string
+	var currentStatus models.Status
 	for _, s := range m.sites {
 		if s.ID == msg.siteID {
 			currentStatus = s.Status
diff --git a/internal/tui/update_test.go b/internal/tui/update_test.go
index cc82a49..f08338d 100644
--- a/internal/tui/update_test.go
+++ b/internal/tui/update_test.go
@@ -8,6 +8,7 @@ import (
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/monitor"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/store/storetest"
 	tea "github.com/charmbracelet/bubbletea"
 	zone "github.com/lrstanley/bubblezone"
 )
@@ -15,13 +16,14 @@ import (
 // --- minimal Store mock for TUI data-flow tests ---
 
 type tuiMockStore struct {
+	storetest.BaseMock
 	alerts           []models.AlertConfig
 	users            []models.User
 	nodes            []models.ProbeNode
 	maint            []models.MaintenanceWindow
 	stateChanges     []models.StateChange
-	stateChangeCalls int // counts GetStateChanges hits (to prove View does no IO)
-	deleteSiteCalls  int // counts DeleteSite hits (to prove writes run in Cmds)
+	stateChangeCalls int
+	deleteSiteCalls  int
 }
 
 func (m *tuiMockStore) GetAllAlerts(_ context.Context) ([]models.AlertConfig, error) {
@@ -38,94 +40,10 @@ func (m *tuiMockStore) GetStateChanges(_ context.Context, _ int, _ int) ([]model
 func (m *tuiMockStore) GetAllMaintenanceWindows(_ context.Context, _ int) ([]models.MaintenanceWindow, error) {
 	return m.maint, nil
 }
-
-func (m *tuiMockStore) Init(_ context.Context) error                            { return nil }
-func (m *tuiMockStore) GetSites(_ context.Context) ([]models.Site, error)       { return nil, nil }
-func (m *tuiMockStore) AddSite(_ context.Context, _ models.Site) error          { return nil }
-func (m *tuiMockStore) UpdateSite(_ context.Context, _ models.Site) error       { return nil }
-func (m *tuiMockStore) UpdateSitePaused(_ context.Context, _ int, _ bool) error { return nil }
 func (m *tuiMockStore) DeleteSite(_ context.Context, _ int) error {
 	m.deleteSiteCalls++
 	return nil
 }
-func (m *tuiMockStore) GetAlert(_ context.Context, _ int) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
-}
-func (m *tuiMockStore) AddAlert(_ context.Context, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *tuiMockStore) UpdateAlert(_ context.Context, _ int, _ string, _ string, _ map[string]string) error {
-	return nil
-}
-func (m *tuiMockStore) DeleteAlert(_ context.Context, _ int) error { return nil }
-func (m *tuiMockStore) GetSiteByName(_ context.Context, _ string) (models.Site, error) {
-	return models.Site{}, nil
-}
-func (m *tuiMockStore) GetAlertByName(_ context.Context, _ string) (models.AlertConfig, error) {
-	return models.AlertConfig{}, nil
-}
-func (m *tuiMockStore) AddSiteReturningID(_ context.Context, _ models.Site) (int, error) {
-	return 0, nil
-}
-func (m *tuiMockStore) AddAlertReturningID(_ context.Context, _ string, _ string, _ map[string]string) (int, error) {
-	return 0, nil
-}
-func (m *tuiMockStore) AddUser(_ context.Context, _ string, _ string, _ string) error { return nil }
-func (m *tuiMockStore) UpdateUser(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *tuiMockStore) DeleteUser(_ context.Context, _ int) error                 { return nil }
-func (m *tuiMockStore) SaveCheck(_ context.Context, _ int, _ int64, _ bool) error { return nil }
-func (m *tuiMockStore) SaveCheckFromNode(_ context.Context, _ int, _ string, _ int64, _ bool) error {
-	return nil
-}
-func (m *tuiMockStore) LoadAllHistory(_ context.Context, _ int) (map[int][]models.CheckRecord, error) {
-	return nil, nil
-}
-func (m *tuiMockStore) PruneCheckHistory(_ context.Context) error { return nil }
-func (m *tuiMockStore) SaveStateChange(_ context.Context, _ int, _ string, _ string, _ string) error {
-	return nil
-}
-func (m *tuiMockStore) GetStateChangesSince(_ context.Context, _ int, _ time.Time) ([]models.StateChange, error) {
-	return nil, nil
-}
-func (m *tuiMockStore) PruneStateChanges(_ context.Context) error                { return nil }
-func (m *tuiMockStore) RegisterNode(_ context.Context, _ models.ProbeNode) error { return nil }
-func (m *tuiMockStore) GetNode(_ context.Context, _ string) (models.ProbeNode, error) {
-	return models.ProbeNode{}, nil
-}
-func (m *tuiMockStore) UpdateNodeLastSeen(_ context.Context, _ string) error { return nil }
-func (m *tuiMockStore) DeleteNode(_ context.Context, _ string) error         { return nil }
-func (m *tuiMockStore) LoadAlertHealth(_ context.Context) (map[int]models.AlertHealthRecord, error) {
-	return nil, nil
-}
-func (m *tuiMockStore) SaveAlertHealth(_ context.Context, _ models.AlertHealthRecord) error {
-	return nil
-}
-func (m *tuiMockStore) SaveLog(_ context.Context, _ string) error           { return nil }
-func (m *tuiMockStore) LoadLogs(_ context.Context, _ int) ([]string, error) { return nil, nil }
-func (m *tuiMockStore) PruneLogs(_ context.Context) error                   { return nil }
-func (m *tuiMockStore) GetActiveMaintenanceWindows(_ context.Context) ([]models.MaintenanceWindow, error) {
-	return nil, nil
-}
-func (m *tuiMockStore) AddMaintenanceWindow(_ context.Context, _ models.MaintenanceWindow) error {
-	return nil
-}
-func (m *tuiMockStore) EndMaintenanceWindow(_ context.Context, _ int) error    { return nil }
-func (m *tuiMockStore) DeleteMaintenanceWindow(_ context.Context, _ int) error { return nil }
-func (m *tuiMockStore) PruneExpiredMaintenanceWindows(_ context.Context, _ time.Duration) (int64, error) {
-	return 0, nil
-}
-func (m *tuiMockStore) IsMonitorInMaintenance(_ context.Context, _ int) (bool, error) {
-	return false, nil
-}
-func (m *tuiMockStore) GetPreference(_ context.Context, _ string) (string, error) { return "", nil }
-func (m *tuiMockStore) SetPreference(_ context.Context, _ string, _ string) error { return nil }
-func (m *tuiMockStore) ExportData(_ context.Context) (models.Backup, error) {
-	return models.Backup{}, nil
-}
-func (m *tuiMockStore) ImportData(_ context.Context, _ models.Backup) error { return nil }
-func (m *tuiMockStore) Close() error                                        { return nil }
 
 func newTestModel(ms *tuiMockStore) Model {
 	return Model{
diff --git a/internal/tui/view_dashboard.go b/internal/tui/view_dashboard.go
index 18fd814..4335dad 100644
--- a/internal/tui/view_dashboard.go
+++ b/internal/tui/view_dashboard.go
@@ -6,6 +6,7 @@ import (
 	"strings"
 	"time"
 
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
 	"github.com/charmbracelet/lipgloss"
 )
 
@@ -16,7 +17,7 @@ func sinApprox(x float64) float64 {
 func (m Model) pulseIndicator() string {
 	hasDown := false
 	for _, s := range m.sites {
-		if !s.Paused && !m.isMonitorInMaintenance(s.ID) && (s.Status == "DOWN" || s.Status == "SSL EXP") {
+		if !s.Paused && !m.isMonitorInMaintenance(s.ID) && (s.Status == models.StatusDown || s.Status == models.StatusSSLExp) {
 			hasDown = true
 			break
 		}
@@ -127,9 +128,9 @@ func (m Model) computeStats() dashboardStats {
 			continue
 		}
 		switch site.Status {
-		case "DOWN", "SSL EXP":
+		case models.StatusDown, models.StatusSSLExp:
 			s.downCount++
-		case "LATE":
+		case models.StatusLate:
 			s.lateCount++
 		}
 	}
diff --git a/internal/tui/view_detail.go b/internal/tui/view_detail.go
index 44c9abf..081fd40 100644
--- a/internal/tui/view_detail.go
+++ b/internal/tui/view_detail.go
@@ -45,7 +45,7 @@ func (m Model) viewDetailPanel() string {
 
 	row("Status", m.fmtStatus(site.Status, site.Paused, m.isMonitorInMaintenance(site.ID)))
 
-	if (site.Status == "DOWN" || site.Status == "SSL EXP" || site.Status == "LATE" || site.Status == "STALE") && site.LastError != "" {
+	if (site.Status == models.StatusDown || site.Status == models.StatusSSLExp || site.Status == models.StatusLate || site.Status == models.StatusStale) && site.LastError != "" {
 		errWidth := m.termWidth - chromePadH - 19
 		if errWidth < 30 {
 			errWidth = 30
@@ -58,7 +58,7 @@ func (m Model) viewDetailPanel() string {
 		row("HTTP Code", strconv.Itoa(site.StatusCode))
 	}
 
-	if (site.Status == "DOWN" || site.Status == "SSL EXP") && site.LastError != "" {
+	if (site.Status == models.StatusDown || site.Status == models.StatusSSLExp) && site.LastError != "" {
 		chain := connectionChain(site.LastError, site.Type, site.StatusCode, strings.HasPrefix(site.URL, "https"))
 		if len(chain) > 0 {
 			b.WriteString("\n")
@@ -189,7 +189,7 @@ func (m Model) viewDetailPanel() string {
 		for i, sc := range stateChanges {
 			ago := fmtDuration(time.Since(sc.ChangedAt))
 			arrow := m.st.subtleStyle.Render(sc.FromStatus) + " → "
-			if sc.ToStatus == "UP" {
+			if sc.ToStatus == string(models.StatusUp) {
 				arrow += m.st.specialStyle.Render(sc.ToStatus)
 			} else {
 				arrow += m.st.dangerStyle.Render(sc.ToStatus)
@@ -198,7 +198,7 @@ func (m Model) viewDetailPanel() string {
 			if dur := computeOutageDuration(stateChanges, i); dur > 0 {
 				line += "  " + m.st.warnStyle.Render("outage "+fmtDuration(dur))
 			}
-			if sc.ErrorReason != "" && sc.ToStatus != "UP" {
+			if sc.ErrorReason != "" && sc.ToStatus != string(models.StatusUp) {
 				line += "  " + m.st.dangerStyle.Render(sc.ErrorReason)
 			}
 			b.WriteString(line + "\n")
diff --git a/internal/tui/view_history.go b/internal/tui/view_history.go
index f61d7d6..9efddcb 100644
--- a/internal/tui/view_history.go
+++ b/internal/tui/view_history.go
@@ -17,14 +17,14 @@ type historyStats struct {
 
 func computeOutageDuration(changes []models.StateChange, idx int) time.Duration {
 	sc := changes[idx]
-	if sc.ToStatus != "UP" {
+	if sc.ToStatus != string(models.StatusUp) {
 		return 0
 	}
 	if idx+1 >= len(changes) {
 		return 0
 	}
 	prev := changes[idx+1]
-	if prev.ToStatus == "UP" {
+	if prev.ToStatus == string(models.StatusUp) {
 		return 0
 	}
 	dur := sc.ChangedAt.Sub(prev.ChangedAt)
@@ -122,11 +122,11 @@ func (m Model) buildHistoryContent() string {
 
 		arrow := m.st.subtleStyle.Render(sc.FromStatus) + " → "
 		switch sc.ToStatus {
-		case "UP":
+		case string(models.StatusUp):
 			arrow += m.st.specialStyle.Render(sc.ToStatus)
-		case "LATE":
+		case string(models.StatusLate):
 			arrow += m.st.warnStyle.Render(sc.ToStatus)
-		case "STALE":
+		case string(models.StatusStale):
 			arrow += m.st.staleStyle.Render(sc.ToStatus)
 		default:
 			arrow += m.st.dangerStyle.Render(sc.ToStatus)
@@ -138,7 +138,7 @@ func (m Model) buildHistoryContent() string {
 		}
 
 		reason := ""
-		if sc.ErrorReason != "" && sc.ToStatus != "UP" {
+		if sc.ErrorReason != "" && sc.ToStatus != string(models.StatusUp) {
 			reason = m.st.dangerStyle.Render(limitStr(sc.ErrorReason, reasonWidth))
 		}