fix: restore missing keybinding validation guards

persistence.ts imported isActionWithOptionalArgs and isShortcutKey,
neither of which existed at runtime — loading persisted custom
keybindings would crash. Adds actions/guards.ts (excluding required-args
actions per TActionArgsMap) and isShortcutKey in keybinding.ts; the nine
previously dead persistence tests now pass.

1 files changed, 29 insertions, 0 deletions

diff --git a/apps/web/src/actions/guards.ts b/apps/web/src/actions/guards.ts
new file mode 100644
index 00000000..c4fbe8a7
--- /dev/null
+++ b/apps/web/src/actions/guards.ts
@@ -0,0 +1,29 @@
+import { ACTIONS } from "./definitions";
+import type { TActionArgsMap, TActionWithOptionalArgs } from "./types";
+
+type TActionWithRequiredArgs = {
+	[K in keyof TActionArgsMap]: undefined extends TActionArgsMap[K]
+		? never
+		: K;
+}[keyof TActionArgsMap];
+
+/**
+ * Actions that require arguments cannot be bound to a shortcut key — a key
+ * press has no way to supply them. Keep in sync with the required (non-
+ * optional) members of `TActionArgsMap`; the type annotation rejects keys
+ * that are not actually required-args actions.
+ */
+const ACTIONS_WITH_REQUIRED_ARGS: readonly TActionWithRequiredArgs[] = [
+	"remove-media-asset",
+	"remove-media-assets",
+];
+
+export function isActionWithOptionalArgs(
+	action: unknown,
+): action is TActionWithOptionalArgs {
+	return (
+		typeof action === "string" &&
+		action in ACTIONS &&
+		!(ACTIONS_WITH_REQUIRED_ARGS as readonly string[]).includes(action)
+	);
+}