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/add.go

@@ -17,7 +17,7 @@ var addCmd = &cobra.Command{
 	RunE:  runAdd,
 }
 
-func runAdd(_ *cobra.Command, args []string) error {
+func runAdd(cmd *cobra.Command, args []string) error {
 	input := strings.Join(args, " ")
 
 	parsed, err := parse.Parse(input)
@@ -47,7 +47,7 @@ func runAdd(_ *cobra.Command, args []string) error {
 		e.CardType = &ct
 	}
 
-	if err := store.Create(e); err != nil {
+	if err := store.Create(cmd.Context(), e); err != nil {
 		return err
 	}