refactor(core): remove store global singleton, thread store explicitly

Remove store.Get()/SetGlobal()/Current. Store is now passed explicitly
to all consumers via constructor parameters and function arguments.

- TUI Model holds store field, set via InitialModel(isAdmin, store)
- monitor.StartEngine(s) and InitHistoryFromStore(s) accept store
- server.Start(cfg, s) closes over store in HTTP handlers
- main.go threads store to SSH server, TUI, monitor, server
- isKeyAllowed receives store as parameter

No more hidden dependency on package-level mutable state in store pkg.
Monitor package still uses package-level state (LiveState, etc.) — will
be encapsulated into Engine struct in Phase 7.

cmd/goupkeep/main.go

@@ -97,8 +97,6 @@ func main() {
 		fmt.Printf("Database init error: %v\n", err)
 		os.Exit(1)
 	}
-	store.SetGlobal(s)
-
 	if *demo {
 		seedDemoData(s)
 	}
@@ -117,15 +115,15 @@ func main() {
 		fmt.Printf("Imported %d monitors and %d alerts from Uptime Kuma v%s\n", len(backup.Sites), len(backup.Alerts), kb.Version)
 	}
 
-	monitor.InitHistoryFromStore()
+	monitor.InitHistoryFromStore(s)
-	monitor.StartEngine()
+	monitor.StartEngine(s)
 
 	server.Start(server.ServerConfig{
 		Port:         httpPort,
 		EnableStatus: enableStatus,
 		Title:        statusTitle,
 		ClusterKey:   clusterKey,
-	})
+	}, s)
 
 	cluster.Start(cluster.Config{
 		Mode:      clusterMode,
@@ -133,10 +131,10 @@ func main() {
 		SharedKey: clusterKey,
 	})
 
-	startSSHServer(*port)
+	startSSHServer(*port, s)
 
 	if isatty.IsTerminal(os.Stdout.Fd()) || isatty.IsCygwinTerminal(os.Stdout.Fd()) {
-		p := tea.NewProgram(tui.InitialModel(true), tea.WithAltScreen(), tea.WithMouseCellMotion())
+		p := tea.NewProgram(tui.InitialModel(true, s), tea.WithAltScreen(), tea.WithMouseCellMotion())
 		if _, err := p.Run(); err != nil {
 			fmt.Printf("Error: %v\n", err)
 		}
@@ -149,16 +147,16 @@ func main() {
 	}
 }
 
-func startSSHServer(port int) {
+func startSSHServer(port int, db store.Store) {
 	s, err := wish.NewServer(
 		wish.WithAddress(fmt.Sprintf(":%d", port)),
 		wish.WithHostKeyPath(".ssh/id_ed25519"),
 		wish.WithPublicKeyAuth(func(ctx ssh.Context, key ssh.PublicKey) bool {
-			return isKeyAllowed(key)
+			return isKeyAllowed(db, key)
 		}),
 		wish.WithMiddleware(
 			bm.Middleware(func(s ssh.Session) (tea.Model, []tea.ProgramOption) {
-				return tui.InitialModel(false), []tea.ProgramOption{tea.WithAltScreen(), tea.WithMouseCellMotion()}
+				return tui.InitialModel(false, db), []tea.ProgramOption{tea.WithAltScreen(), tea.WithMouseCellMotion()}
 			}),
 		),
 	)
@@ -206,8 +204,8 @@ func seedDemoData(s store.Store) {
 	s.AddSite(models.Site{Name: "SSH Server", Type: "port", Interval: 60, AlertID: alertID, Hostname: "10.0.0.1", Port: 22, Timeout: 5, ExpiryThreshold: 7})
 }
 
-func isKeyAllowed(incomingKey ssh.PublicKey) bool {
+func isKeyAllowed(db store.Store, incomingKey ssh.PublicKey) bool {
-	users, err := store.Get().GetAllUsers()
+	users, err := db.GetAllUsers()
 	if err != nil {
 		return false
 	}

internal/monitor/history.go

@@ -20,11 +20,7 @@ var (
 	historyMu sync.RWMutex
 )
 
-func InitHistoryFromStore() {
+func InitHistoryFromStore(s store.Store) {
-	s := store.Get()
-	if s == nil {
-		return
-	}
 	all, err := s.LoadAllHistory(maxHistoryLen)
 	if err != nil {
 		AddLog("Failed to load check history: " + err.Error())
@@ -74,8 +70,8 @@ func RecordCheck(siteID int, latency time.Duration, isUp bool) {
 		h.Statuses = h.Statuses[len(h.Statuses)-maxHistoryLen:]
 	}
 
-	if s := store.Get(); s != nil {
+	if db != nil {
-		go func() { _ = s.SaveCheck(siteID, latency.Nanoseconds(), isUp) }()
+		go func() { _ = db.SaveCheck(siteID, latency.Nanoseconds(), isUp) }()
 	}
 }
 

internal/monitor/monitor.go

@@ -55,6 +55,8 @@ var (
 
 	insecureSkipVerify bool
 
+	db store.Store
+
 	strictClient = &http.Client{
 		Transport: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: false}},
 	}
@@ -119,16 +121,11 @@ func RecordHeartbeat(token string) bool {
 	return true
 }
 
-func StartEngine() {
+func StartEngine(s store.Store) {
+	db = s
 	go func() {
 		for {
-			s_instance := store.Get()
+			sites, err := db.GetSites()
-			if s_instance == nil {
-				time.Sleep(1 * time.Second)
-				continue
-			}
-
-			sites, err := s_instance.GetSites()
 			if err != nil {
 				AddLog(fmt.Sprintf("Failed to load sites: %v", err))
 				time.Sleep(5 * time.Second)
@@ -407,11 +404,10 @@ func handleStatusChange(site models.Site, rawStatus string, code int, latency ti
 }
 
 func triggerAlert(alertID int, title, message string) {
-	s_instance := store.Get()
+	if db == nil {
-	if s_instance == nil {
 		return
 	}
-	cfg, err := s_instance.GetAlert(alertID)
+	cfg, err := db.GetAlert(alertID)
 	if err != nil {
 		return
 	}

internal/server/server.go

@@ -148,7 +148,7 @@ type ServerConfig struct {
 	ClusterKey   string // Shared Secret for Security
 }
 
-func Start(cfg ServerConfig) {
+func Start(cfg ServerConfig, s store.Store) {
 	if cfg.ClusterKey == "" {
 		fmt.Println("WARNING: No UPKEEP_CLUSTER_SECRET set. Cluster API endpoints are unauthenticated.")
 	}
@@ -185,7 +185,7 @@ func Start(cfg ServerConfig) {
 			http.Error(w, "Unauthorized: UPKEEP_CLUSTER_SECRET required", 401)
 			return
 		}
-		data, err := store.Get().ExportData()
+		data, err := s.ExportData()
 		if err != nil {
 			log.Printf("Export failed: %v", err)
 			http.Error(w, "Export failed", 500)
@@ -209,7 +209,7 @@ func Start(cfg ServerConfig) {
 			http.Error(w, "Invalid JSON", 400)
 			return
 		}
-		if err := store.Get().ImportData(data); err != nil {
+		if err := s.ImportData(data); err != nil {
 			log.Printf("Import failed: %v", err)
 			http.Error(w, "Import failed", 500)
 			return
@@ -234,7 +234,7 @@ func Start(cfg ServerConfig) {
 			return
 		}
 		backup := importer.ConvertKuma(&kb)
-		if err := store.Get().ImportData(backup); err != nil {
+		if err := s.ImportData(backup); err != nil {
 			log.Printf("Kuma import failed: %v", err)
 			http.Error(w, "Import failed", 500)
 			return

internal/store/store.go

@@ -35,13 +35,3 @@ type Store interface {
 	ExportData() (models.Backup, error)
 	ImportData(data models.Backup) error
 }
-
-var Current Store
-
-func SetGlobal(s Store) {
-	Current = s
-}
-
-func Get() Store {
-	return Current
-}

internal/tui/tab_alerts.go

@@ -3,7 +3,6 @@ package tui
 import (
 	"fmt"
 	"go-upkeep/internal/monitor"
-	"go-upkeep/internal/store"
 
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/huh"
@@ -278,11 +277,11 @@ func (m *Model) submitAlertForm() {
 	}
 
 	if m.editID > 0 {
-		if err := store.Get().UpdateAlert(m.editID, d.Name, d.AlertType, settings); err != nil {
+		if err := m.store.UpdateAlert(m.editID, d.Name, d.AlertType, settings); err != nil {
 			monitor.AddLog("Update alert failed: " + err.Error())
 		}
 	} else {
-		if err := store.Get().AddAlert(d.Name, d.AlertType, settings); err != nil {
+		if err := m.store.AddAlert(d.Name, d.AlertType, settings); err != nil {
 			monitor.AddLog("Add alert failed: " + err.Error())
 		}
 	}

internal/tui/tab_sites.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"go-upkeep/internal/models"
 	"go-upkeep/internal/monitor"
-	"go-upkeep/internal/store"
 	"net/url"
 	"strconv"
 	"strings"
@@ -361,8 +360,7 @@ func (m *Model) initSiteHuhForm() tea.Cmd {
 	}
 
 	alertOpts := []huh.Option[string]{huh.NewOption("None", "0")}
-	if s := store.Get(); s != nil {
+	if alerts, err := m.store.GetAllAlerts(); err == nil {
-		if alerts, err := s.GetAllAlerts(); err == nil {
 		for _, a := range alerts {
 			alertOpts = append(alertOpts, huh.NewOption(
 				fmt.Sprintf("%s (%s)", a.Name, a.Type),
@@ -370,7 +368,6 @@ func (m *Model) initSiteHuhForm() tea.Cmd {
 			))
 		}
 	}
-	}
 
 	groupOpts := []huh.Option[string]{huh.NewOption("None", "0")}
 	for _, s := range m.sites {
@@ -560,12 +557,12 @@ func (m *Model) submitSiteForm() {
 	}
 
 	if m.editID > 0 {
-		if err := store.Get().UpdateSite(site); err != nil {
+		if err := m.store.UpdateSite(site); err != nil {
 			monitor.AddLog("Update site failed: " + err.Error())
 		}
 		monitor.UpdateSiteConfig(site)
 	} else {
-		if err := store.Get().AddSite(site); err != nil {
+		if err := m.store.AddSite(site); err != nil {
 			monitor.AddLog("Add site failed: " + err.Error())
 		}
 	}

internal/tui/tab_users.go

@@ -3,7 +3,6 @@ package tui
 import (
 	"fmt"
 	"go-upkeep/internal/monitor"
-	"go-upkeep/internal/store"
 
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/huh"
@@ -146,11 +145,11 @@ func (m *Model) initUserHuhForm() tea.Cmd {
 func (m *Model) submitUserForm() {
 	d := m.userFormData
 	if m.editID > 0 {
-		if err := store.Get().UpdateUser(m.editID, d.Username, d.PublicKey, d.Role); err != nil {
+		if err := m.store.UpdateUser(m.editID, d.Username, d.PublicKey, d.Role); err != nil {
 			monitor.AddLog("Update user failed: " + err.Error())
 		}
 	} else {
-		if err := store.Get().AddUser(d.Username, d.PublicKey, d.Role); err != nil {
+		if err := m.store.AddUser(d.Username, d.PublicKey, d.Role); err != nil {
 			monitor.AddLog("Add user failed: " + err.Error())
 		}
 	}

internal/tui/tui.go

@@ -68,6 +68,7 @@ type Model struct {
 	deleteTab  int
 
 	collapsed map[int]bool
+	store     store.Store
 
 	// harmonica animation state
 	pulseSpring harmonica.Spring
@@ -80,7 +81,7 @@ type Model struct {
 	users  []models.User
 }
 
-func InitialModel(isAdmin bool) Model {
+func InitialModel(isAdmin bool, s store.Store) Model {
 	vpLogs := viewport.New(100, 20)
 	vpLogs.SetContent("Waiting for logs...")
 	z := zone.New()
@@ -90,6 +91,7 @@ func InitialModel(isAdmin bool) Model {
 		logViewport:  vpLogs,
 		maxTableRows: 5,
 		isAdmin:      isAdmin,
+		store:        s,
 		zones:        z,
 		pulseSpring:  spring,
 		collapsed:    make(map[int]bool),
@@ -107,26 +109,24 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if keyMsg, ok := msg.(tea.KeyMsg); ok {
 			switch keyMsg.String() {
 			case "y", "Y":
-				if s := store.Get(); s != nil {
 				switch m.deleteTab {
 				case 0:
-						if err := s.DeleteSite(m.deleteID); err != nil {
+					if err := m.store.DeleteSite(m.deleteID); err != nil {
 						monitor.AddLog("Delete site failed: " + err.Error())
 					}
 					monitor.RemoveSite(m.deleteID)
 					m.adjustCursor(len(m.sites) - 1)
 				case 1:
-						if err := s.DeleteAlert(m.deleteID); err != nil {
+					if err := m.store.DeleteAlert(m.deleteID); err != nil {
 						monitor.AddLog("Delete alert failed: " + err.Error())
 					}
 					m.adjustCursor(len(m.alerts) - 1)
 				case 3:
-						if err := s.DeleteUser(m.deleteID); err != nil {
+					if err := m.store.DeleteUser(m.deleteID); err != nil {
 						monitor.AddLog("Delete user failed: " + err.Error())
 					}
 					m.adjustCursor(len(m.users) - 1)
 				}
-				}
 				m.refreshData()
 				m.state = stateDashboard
 				if m.deleteTab == 3 {
@@ -319,9 +319,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 					site := m.sites[m.cursor]
 					monitor.ToggleSitePause(site.ID)
 					site.Paused = !site.Paused
-					if s := store.Get(); s != nil {
+					_ = m.store.UpdateSitePaused(site.ID, site.Paused)
-						_ = s.UpdateSitePaused(site.ID, site.Paused)
-					}
 					m.refreshData()
 				}
 			case "d", "backspace":
@@ -470,23 +468,18 @@ func (m *Model) refreshData() {
 	}
 	ordered = append(ordered, ungrouped...)
 	m.sites = ordered
-	if s := store.Get(); s != nil {
+	if alerts, err := m.store.GetAllAlerts(); err == nil {
-		if alerts, err := s.GetAllAlerts(); err == nil {
 		m.alerts = alerts
 	}
 	if m.isAdmin {
-			if users, err := s.GetAllUsers(); err == nil {
+		if users, err := m.store.GetAllUsers(); err == nil {
 			m.users = users
 		}
 	}
-	}
 	m.logViewport.SetContent(strings.Join(monitor.GetLogs(), "\n"))
 }
 
 func (m *Model) submitForm() {
-	if store.Get() == nil {
-		return
-	}
 	switch m.state {
 	case stateFormSite:
 		if m.siteFormData != nil {