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/ls.go

@@ -36,7 +36,7 @@ func init() {
 	lsCmd.Flags().BoolVar(&lsAll, "all", false, "include deleted entities")
 }
 
-func runLs(_ *cobra.Command, _ []string) error {
+func runLs(cmd *cobra.Command, _ []string) error {
 	store, err := openStore()
 	if err != nil {
 		return err
@@ -88,7 +88,7 @@ func runLs(_ *cobra.Command, _ []string) error {
 		p.Since = &since
 	}
 
-	entities, err := store.List(p)
+	entities, err := store.List(cmd.Context(), p)
 	if err != nil {
 		return err
 	}