refactor(db): thread context.Context through all Store methods

Enables request-scoped cancellation, timeouts, and graceful shutdown
for all database operations across API handlers, CLI commands, and TUI.

cmd/demo.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -35,7 +36,7 @@ type demoEntity struct {
 	Tags        []string `json:"tags"`
 }
 
-func runDemo(_ *cobra.Command, _ []string) error {
+func runDemo(cmd *cobra.Command, _ []string) error {
 	tmpDir, err := os.MkdirTemp("", "nib-demo-*")
 	if err != nil {
 		return err
@@ -48,7 +49,7 @@ func runDemo(_ *cobra.Command, _ []string) error {
 		return err
 	}
 
-	if err := seedDemo(store); err != nil {
+	if err := seedDemo(cmd.Context(), store); err != nil {
 		store.Close()
 		return fmt.Errorf("seed demo data: %w", err)
 	}
@@ -58,7 +59,7 @@ func runDemo(_ *cobra.Command, _ []string) error {
 	return runServe(nil, nil)
 }
 
-func seedDemo(store *db.Store) error {
+func seedDemo(ctx context.Context, store *db.Store) error {
 	data, err := findDemoFile()
 	if err != nil {
 		return err
@@ -94,19 +95,19 @@ func seedDemo(store *db.Store) error {
 			e.CompletedAt = &t
 		}
 
-		if err := store.Create(e); err != nil {
+		if err := store.Create(ctx, e); err != nil {
 			return fmt.Errorf("entity %d: %w", i, err)
 		}
 
 		if entry.CardType != nil {
 			ct := db.CardType(*entry.CardType)
-			if err := store.Promote(e.ID, ct, entry.CardData); err != nil {
+			if err := store.Promote(ctx, e.ID, ct, entry.CardData); err != nil {
 				return fmt.Errorf("promote entity %d: %w", i, err)
 			}
 		}
 
 		if entry.Deleted {
-			store.SoftDelete(e.ID)
+			store.SoftDelete(ctx, e.ID)
 		}
 	}