refactor: propagate context.Context through call chains

Thread context.Context from callers instead of creating
context.Background() at every call site. Engine stores its
lifecycle ctx for use by triggerAlert goroutines. TUI Model
carries ctx for store operations in Cmd closures. CLI commands
create a root ctx and thread it through openStore, seed
functions, and init methods.

Only two intentional context.Background() remain in non-root
positions: engine constructor default (overridden by Start)
and drainWrites (parent already cancelled at shutdown).

internal/monitor/alerts.go

@@ -19,8 +19,8 @@ type AlertHealth struct {
 
 // InitAlertHealth restores persisted alert send health so the dashboard shows real
 // "last sent" / health state on startup instead of resetting every channel to "never".
-func (e *Engine) InitAlertHealth() {
-	records, err := e.db.LoadAlertHealth(context.Background())
+func (e *Engine) InitAlertHealth(ctx context.Context) {
+	records, err := e.db.LoadAlertHealth(ctx)
 	if err != nil {
 		return
 	}
@@ -198,7 +198,7 @@ func (e *Engine) triggerAlert(alertID int, title, message string) {
 	if alertID <= 0 {
 		return
 	}
-	cfg, err := e.db.GetAlert(context.Background(), alertID)
+	cfg, err := e.db.GetAlert(e.ctx, alertID)
 	if err != nil {
 		e.AddLog(fmt.Sprintf("Failed to load alert config %d: %v", alertID, err))
 		return
@@ -206,7 +206,7 @@ func (e *Engine) triggerAlert(alertID int, title, message string) {
 	provider := alert.GetProvider(cfg)
 	if provider != nil {
 		go func() {
-			ctx, cancel := context.WithTimeout(context.Background(), alertSendTimeout)
+			ctx, cancel := context.WithTimeout(e.ctx, alertSendTimeout)
 			defer cancel()
 			if err := provider.Send(ctx, title, message); err != nil {
 				e.AddLog(fmt.Sprintf("Alert send failed (%s): %v", cfg.Name, err))
@@ -250,8 +250,8 @@ func (e *Engine) GetAlertHealth(alertID int) AlertHealth {
 	return e.alertHealth[alertID]
 }
 
-func (e *Engine) TestAlert(alertID int) error {
-	cfg, err := e.db.GetAlert(context.Background(), alertID)
+func (e *Engine) TestAlert(ctx context.Context, alertID int) error {
+	cfg, err := e.db.GetAlert(ctx, alertID)
 	if err != nil {
 		return fmt.Errorf("failed to load alert: %w", err)
 	}
@@ -259,7 +259,7 @@ func (e *Engine) TestAlert(alertID int) error {
 	if provider == nil {
 		return fmt.Errorf("no provider for type %q", cfg.Type)
 	}
-	ctx, cancel := context.WithTimeout(context.Background(), alertSendTimeout)
+	ctx, cancel := context.WithTimeout(ctx, alertSendTimeout)
 	defer cancel()
 	err = provider.Send(ctx, "🧪 Test Alert", fmt.Sprintf("Test notification from uptop for channel '%s'.", cfg.Name))
 	if err != nil {

internal/monitor/history.go

@@ -14,8 +14,8 @@ type SiteHistory struct {
 	UpChecks    int
 }
 
-func (e *Engine) InitHistory() {
-	all, err := e.db.LoadAllHistory(context.Background(), maxHistoryLen)
+func (e *Engine) InitHistory(ctx context.Context) {
+	all, err := e.db.LoadAllHistory(ctx, maxHistoryLen)
 	if err != nil {
 		e.AddLog("Failed to load check history: " + err.Error())
 		return

internal/monitor/monitor.go

@@ -64,6 +64,7 @@ type Engine struct {
 	dbWrites  chan dbWrite
 	writerWG  sync.WaitGroup
 	checkerWG sync.WaitGroup
+	ctx       context.Context
 	cancel    context.CancelFunc
 	stopOnce  sync.Once
 }
@@ -90,6 +91,7 @@ func newEngine(s store.Store, allowPrivateTargets bool) *Engine {
 		allowPrivateTargets: allowPrivateTargets,
 		maintRetention:      defaultMaintRetention,
 		dbWrites:            make(chan dbWrite, dbWriteBuffer),
+		ctx:                 context.Background(),
 		db:                  s,
 		strictClient: &http.Client{
 			Transport: &http.Transport{
@@ -200,6 +202,8 @@ func (e *Engine) dbWriter(ctx context.Context) {
 }
 
 // drainWrites flushes everything still buffered, best-effort, at shutdown.
+// Uses context.Background because the engine ctx is already cancelled when
+// this runs — writes still need to reach the DB.
 func (e *Engine) drainWrites() {
 	for {
 		select {
@@ -238,8 +242,8 @@ func (e *Engine) Stop() {
 	})
 }
 
-func (e *Engine) InitLogs() {
-	entries, err := e.db.LoadLogs(context.Background(), maxLogEntries)
+func (e *Engine) InitLogs(ctx context.Context) {
+	entries, err := e.db.LoadLogs(ctx, maxLogEntries)
 	if err != nil {
 		return
 	}
@@ -264,6 +268,7 @@ func (e *Engine) Start(ctx context.Context) {
 	// trace the cross-method call, and cancelling the parent reaps this child
 	// regardless, so the leak it warns about can't occur.
 	ctx, e.cancel = context.WithCancel(ctx) //nolint:gosec // cancel is called in Stop()
+	e.ctx = ctx
 
 	e.writerWG.Add(1)
 	go e.dbWriter(ctx)

internal/monitor/monitor_test.go

@@ -208,7 +208,7 @@ func TestInitHistory_LoadsFromDB(t *testing.T) {
 		{SiteID: 1, LatencyNs: 3000000, IsUp: false},
 	}
 	e := newTestEngine(ms)
-	e.InitHistory()
+	e.InitHistory(context.Background())
 
 	h, ok := e.GetHistory(1)
 	if !ok {
@@ -248,7 +248,7 @@ func TestInitLogs_LoadsFromDB(t *testing.T) {
 		{Message: "old-log-2"},
 	}
 	e := newTestEngine(ms)
-	e.InitLogs()
+	e.InitLogs(context.Background())
 
 	logs := e.GetLogs()
 	if len(logs) != 2 {

internal/monitor/sites.go

@@ -141,16 +141,16 @@ func (e *Engine) GetDisplayStatus(site models.Site) string {
 	return string(site.Status)
 }
 
-func (e *Engine) GetStateChanges(siteID int, limit int) []models.StateChange {
-	changes, err := e.db.GetStateChanges(context.Background(), siteID, limit)
+func (e *Engine) GetStateChanges(ctx context.Context, siteID int, limit int) []models.StateChange {
+	changes, err := e.db.GetStateChanges(ctx, siteID, limit)
 	if err != nil {
 		return nil
 	}
 	return changes
 }
 
-func (e *Engine) GetStateChangesSince(siteID int, since time.Time) []models.StateChange {
-	changes, err := e.db.GetStateChangesSince(context.Background(), siteID, since)
+func (e *Engine) GetStateChangesSince(ctx context.Context, siteID int, since time.Time) []models.StateChange {
+	changes, err := e.db.GetStateChangesSince(ctx, siteID, since)
 	if err != nil {
 		return nil
 	}

internal/tui/data.go

@@ -13,9 +13,9 @@ import (
 	tea "github.com/charmbracelet/bubbletea"
 )
 
-func loadCollapsed(s store.Store) map[int]bool {
+func loadCollapsed(ctx context.Context, s store.Store) map[int]bool {
 	m := make(map[int]bool)
-	raw, err := s.GetPreference(context.Background(), "collapsed_groups")
+	raw, err := s.GetPreference(ctx, "collapsed_groups")
 	if err != nil || raw == "" {
 		return m
 	}
@@ -163,9 +163,9 @@ func (m *Model) loadTabDataCmd() tea.Cmd {
 	m.tabSeq++
 	seq := m.tabSeq
 	st := m.store
+	ctx := m.ctx
 	isAdmin := m.isAdmin
 	return func() tea.Msg {
-		ctx := context.Background()
 		alerts, err := st.GetAllAlerts(ctx)
 		if err != nil {
 			return tabDataMsg{seq: seq, err: err}
@@ -192,6 +192,7 @@ func (m *Model) loadTabDataCmd() tea.Cmd {
 // goroutine. View renders the cached result rather than querying the DB.
 func (m *Model) loadDetailCmd(siteID int) tea.Cmd {
 	eng := m.engine
+	ctx := m.ctx
 	var currentStatus models.Status
 	for _, s := range m.sites {
 		if s.ID == siteID {
@@ -200,9 +201,9 @@ func (m *Model) loadDetailCmd(siteID int) tea.Cmd {
 		}
 	}
 	return func() tea.Msg {
-		changes := eng.GetStateChanges(siteID, 5)
+		changes := eng.GetStateChanges(ctx, siteID, 5)
 		now := time.Now()
-		allChanges := eng.GetStateChangesSince(siteID, now.Add(-stateHistoryLookback))
+		allChanges := eng.GetStateChangesSince(ctx, siteID, now.Add(-stateHistoryLookback))
 		daily := monitor.ComputeDailyBreakdown(allChanges, currentStatus, stateHistoryDays, now)
 		return detailDataMsg{siteID: siteID, changes: changes, dailyDays: daily}
 	}
@@ -212,8 +213,9 @@ func (m *Model) loadDetailCmd(siteID int) tea.Cmd {
 // the UI goroutine.
 func (m *Model) loadHistoryCmd(siteID int) tea.Cmd {
 	eng := m.engine
+	ctx := m.ctx
 	return func() tea.Msg {
-		return historyDataMsg{siteID: siteID, changes: eng.GetStateChanges(siteID, stateHistoryLimit)}
+		return historyDataMsg{siteID: siteID, changes: eng.GetStateChanges(ctx, siteID, stateHistoryLimit)}
 	}
 }
 
@@ -222,12 +224,13 @@ func (m *Model) loadHistoryCmd(siteID int) tea.Cmd {
 // can be recognized and dropped.
 func (m *Model) loadSLACmd(siteID, periodIdx int) tea.Cmd {
 	eng := m.engine
+	ctx := m.ctx
 	since := time.Now().Add(-slaPeriods[periodIdx].duration)
 	return func() tea.Msg {
 		return slaDataMsg{
 			siteID:    siteID,
 			periodIdx: periodIdx,
-			changes:   eng.GetStateChangesSince(siteID, since),
+			changes:   eng.GetStateChangesSince(ctx, siteID, since),
 		}
 	}
 }

internal/tui/tab_alerts.go

@@ -1,7 +1,6 @@
 package tui
 
 import (
-	"context"
 	"fmt"
 	neturl "net/url"
 	"sort"
@@ -537,15 +536,16 @@ func (m *Model) submitAlertForm() tea.Cmd {
 	}
 
 	st := m.store
+	ctx := m.ctx
 	id := m.editID
 	name, aType := d.Name, d.AlertType
 	m.state = stateDashboard
 	if id > 0 {
 		return writeCmd("Update alert", func() error {
-			return st.UpdateAlert(context.Background(), id, name, aType, settings)
+			return st.UpdateAlert(ctx, id, name, aType, settings)
 		})
 	}
 	return writeCmd("Add alert", func() error {
-		return st.AddAlert(context.Background(), name, aType, settings)
+		return st.AddAlert(ctx, name, aType, settings)
 	})
 }

internal/tui/tab_maint.go

@@ -1,7 +1,6 @@
 package tui
 
 import (
-	"context"
 	"fmt"
 	"strconv"
 	"time"
@@ -254,9 +253,9 @@ func (m *Model) submitMaintForm() tea.Cmd {
 	}
 
 	st := m.store
+	ctx := m.ctx
 	m.state = stateDashboard
 	return writeCmd("Add maintenance window", func() error {
-		ctx := context.Background()
 		overlaps, _ := st.GetOverlappingMaintenanceWindows(ctx, mw.MonitorID, mw.StartTime, mw.EndTime)
 		if len(overlaps) > 0 {
 			_ = st.SaveLog(ctx, fmt.Sprintf("Overlap: new window %q overlaps with existing %q", mw.Title, overlaps[0].Title))

internal/tui/tab_sites.go

@@ -1,7 +1,6 @@
 package tui
 
 import (
-	"context"
 	"fmt"
 	"net/url"
 	"strconv"
@@ -604,10 +603,11 @@ func (m *Model) submitSiteForm() tea.Cmd {
 	}
 
 	st := m.store
+	ctx := m.ctx
 	m.state = stateDashboard
 	if m.editID > 0 {
 		m.engine.UpdateSiteConfig(cfg)
-		return writeCmd("Update site", func() error { return st.UpdateSite(context.Background(), cfg) })
+		return writeCmd("Update site", func() error { return st.UpdateSite(ctx, cfg) })
 	}
-	return writeCmd("Add site", func() error { return st.AddSite(context.Background(), cfg) })
+	return writeCmd("Add site", func() error { return st.AddSite(ctx, cfg) })
 }

internal/tui/tab_users.go

@@ -1,7 +1,6 @@
 package tui
 
 import (
-	"context"
 	"fmt"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -114,15 +113,16 @@ func (m *Model) initUserHuhForm() tea.Cmd {
 func (m *Model) submitUserForm() tea.Cmd {
 	d := m.userFormData
 	st := m.store
+	ctx := m.ctx
 	id := m.editID
 	username, key, role := d.Username, d.PublicKey, d.Role
 	m.state = stateDashboard
 	if id > 0 {
 		return writeCmd("Update user", func() error {
-			return st.UpdateUser(context.Background(), id, username, key, role)
+			return st.UpdateUser(ctx, id, username, key, role)
 		})
 	}
 	return writeCmd("Add user", func() error {
-		return st.AddUser(context.Background(), username, key, role)
+		return st.AddUser(ctx, username, key, role)
 	})
 }

internal/tui/tui.go

@@ -175,6 +175,7 @@ type Model struct {
 	deleteName string
 	deleteTab  int
 
+	ctx        context.Context
 	collapsed  map[int]bool
 	store      store.Store
 	engine     *monitor.Engine
@@ -213,14 +214,14 @@ type Model struct {
 	version  string
 }
 
-func InitialModel(isAdmin bool, s store.Store, eng *monitor.Engine, version string) Model {
+func InitialModel(ctx context.Context, isAdmin bool, s store.Store, eng *monitor.Engine, version string) Model {
 	vpLogs := viewport.New(100, 20)
 	vpLogs.SetContent("Waiting for logs...")
 	z := zone.New()
 	spring := harmonica.NewSpring(harmonica.FPS(10), 6.0, 0.4)
-	collapsed := loadCollapsed(s)
+	collapsed := loadCollapsed(ctx, s)
 
-	themeName, _ := s.GetPreference(context.Background(), "theme")
+	themeName, _ := s.GetPreference(ctx, "theme")
 	theme := themeByName(themeName)
 	themeIdx := 0
 	for i, t := range themes {
@@ -230,9 +231,10 @@ func InitialModel(isAdmin bool, s store.Store, eng *monitor.Engine, version stri
 		}
 	}
 
-	detailPref, _ := s.GetPreference(context.Background(), "detail_open")
+	detailPref, _ := s.GetPreference(ctx, "detail_open")
 
 	return Model{
+		ctx:             ctx,
 		state:           stateDashboard,
 		logViewport:     vpLogs,
 		maxTableRows:    5,

internal/tui/update.go

@@ -1,7 +1,6 @@
 package tui
 
 import (
-	"context"
 	"fmt"
 	"time"
 
@@ -76,23 +75,24 @@ func (m *Model) handleConfirmDelete(msg tea.Msg) (tea.Model, tea.Cmd) {
 		// writeDoneMsg reload converges the UI back to the DB state (and the
 		// engine poll loop re-adds a site that is still in the DB).
 		st := m.store
+		ctx := m.ctx
 		id := m.deleteID
 		var cmd tea.Cmd
 		switch m.deleteTab {
 		case tabMonitors:
-			cmd = writeCmd("Delete site", func() error { return st.DeleteSite(context.Background(), id) })
+			cmd = writeCmd("Delete site", func() error { return st.DeleteSite(ctx, id) })
 			m.engine.RemoveSite(id)
 			m.adjustCursor(len(m.sites) - 1)
 		case tabMaint:
-			cmd = writeCmd("Delete maintenance window", func() error { return st.DeleteMaintenanceWindow(context.Background(), id) })
+			cmd = writeCmd("Delete maintenance window", func() error { return st.DeleteMaintenanceWindow(ctx, id) })
 			m.adjustCursor(len(m.maintenanceWindows) - 1)
 		case tabSettings:
 			switch m.settingsSection {
 			case sectionAlerts:
-				cmd = writeCmd("Delete alert", func() error { return st.DeleteAlert(context.Background(), id) })
+				cmd = writeCmd("Delete alert", func() error { return st.DeleteAlert(ctx, id) })
 				m.adjustCursor(len(m.alerts) - 1)
 			case sectionUsers:
-				cmd = writeCmd("Delete user", func() error { return st.DeleteUser(context.Background(), id) })
+				cmd = writeCmd("Delete user", func() error { return st.DeleteUser(ctx, id) })
 				m.adjustCursor(len(m.users) - 1)
 			}
 		}
@@ -232,8 +232,9 @@ func (m *Model) handleTabData(msg tabDataMsg) (tea.Model, tea.Cmd) {
 // surfaces through the engine log (picked up by the next refreshLive).
 func (m *Model) testAlertCmd(id int, name string) tea.Cmd {
 	eng := m.engine
+	ctx := m.ctx
 	return func() tea.Msg {
-		if err := eng.TestAlert(id); err != nil {
+		if err := eng.TestAlert(ctx, id); err != nil {
 			eng.AddLog(fmt.Sprintf("Test alert failed (%s): %v", name, err))
 		}
 		return nil
@@ -635,9 +636,10 @@ func (m *Model) handleDashboardKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			m.collapsed[gid] = !m.collapsed[gid]
 			payload := collapsedJSON(m.collapsed)
 			st := m.store
+			ctx := m.ctx
 			m.refreshLive()
 			return m, writeCmd("Save collapsed groups", func() error {
-				return st.SetPreference(context.Background(), "collapsed_groups", payload)
+				return st.SetPreference(ctx, "collapsed_groups", payload)
 			})
 		}
 	case "p":
@@ -645,9 +647,10 @@ func (m *Model) handleDashboardKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			id := m.sites[m.cursor].ID
 			paused := m.engine.ToggleSitePause(id)
 			st := m.store
+			ctx := m.ctx
 			m.refreshLive()
 			return m, writeCmd("Update pause state", func() error {
-				return st.UpdateSitePaused(context.Background(), id, paused)
+				return st.UpdateSitePaused(ctx, id, paused)
 			})
 		}
 	case "i":
@@ -655,6 +658,7 @@ func (m *Model) handleDashboardKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			m.detailOpen = !m.detailOpen
 			m.recalcLayout()
 			st := m.store
+			ctx := m.ctx
 			open := m.detailOpen
 			var cmd tea.Cmd
 			if m.detailOpen {
@@ -665,7 +669,7 @@ func (m *Model) handleDashboardKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 				if open {
 					v = "true"
 				}
-				return st.SetPreference(context.Background(), "detail_open", v)
+				return st.SetPreference(ctx, "detail_open", v)
 			})
 			if cmd != nil {
 				return m, tea.Batch(cmd, saveCmd)
@@ -682,8 +686,9 @@ func (m *Model) handleDashboardKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 				m.detailOpen = false
 				m.recalcLayout()
 				st := m.store
+				ctx := m.ctx
 				return m, writeCmd("Save detail preference", func() error {
-					return st.SetPreference(context.Background(), "detail_open", "false")
+					return st.SetPreference(ctx, "detail_open", "false")
 				})
 			}
 		}
@@ -712,10 +717,11 @@ func (m *Model) handleDashboardKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			isActive := !mw.StartTime.After(now) && (mw.EndTime.IsZero() || mw.EndTime.After(now))
 			if isActive {
 				st := m.store
+				ctx := m.ctx
 				id := mw.ID
 				m.refreshLive()
 				return m, writeCmd("End maintenance", func() error {
-					return st.EndMaintenanceWindow(context.Background(), id)
+					return st.EndMaintenanceWindow(ctx, id)
 				})
 			}
 		}
@@ -724,9 +730,10 @@ func (m *Model) handleDashboardKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		m.theme = themes[m.themeIndex]
 		m.st = newStyles(m.theme)
 		st := m.store
+		ctx := m.ctx
 		name := m.theme.Name
 		return m, writeCmd("Save theme", func() error {
-			return st.SetPreference(context.Background(), "theme", name)
+			return st.SetPreference(ctx, "theme", name)
 		})
 	case "d":
 		return m.handleDeleteItem()