feat(overlay): discover unclaimed mpv key bindings (#246)

src/main/runtime/mpv-input-bindings.ts

@@ -0,0 +1,31 @@
+import type { Keybinding } from '../../types';
+import { parseSessionBindingKey } from '../../core/services/session-bindings';
+import { parseMpvInputBindingKeys } from '../../shared/mpv-input-bindings';
+import type { MpvInputBindingsSnapshot } from '../../types/session-bindings';
+
+export async function readMpvInputBindings(deps: {
+  getMpvClient: () => {
+    connected: boolean;
+    requestProperty: (name: string) => Promise<unknown>;
+  } | null;
+  getConfiguredKeybindings: () => Keybinding[];
+  platform: 'darwin' | 'win32' | 'linux';
+}): Promise<MpvInputBindingsSnapshot> {
+  const blockedKeys = deps.getConfiguredKeybindings().flatMap((binding) => {
+    const { key } = parseSessionBindingKey(binding.key, deps.platform);
+    return key ? [key] : [];
+  });
+  const client = deps.getMpvClient();
+  if (!client?.connected) return { keys: [], blockedKeys };
+  try {
+    const value = await client.requestProperty('input-bindings');
+    return {
+      keys:
+        client === deps.getMpvClient() && client.connected ? parseMpvInputBindingKeys(value) : [],
+      blockedKeys,
+    };
+  } catch {
+    // Older mpv versions and disconnected sessions retain SubMiner's controls.
+    return { keys: [], blockedKeys };
+  }
+}