feat(youtube): add mediaCache mode and safer stream media extraction (#130)

src/config/definitions/defaults-core.ts

@@ -111,6 +111,10 @@ export const CORE_DEFAULT_CONFIG: Pick<
   },
   youtube: {
     primarySubLanguages: ['ja', 'jpn'],
+    mediaCache: {
+      mode: 'direct',
+      maxHeight: 720,
+    },
   },
   subsync: {
     alass_path: '',

src/config/definitions/options-core.ts

@@ -119,6 +119,24 @@ export function buildCoreConfigOptionRegistry(
       description:
         'Comma-separated primary subtitle language priority for managed subtitle auto-selection.',
     },
+    {
+      path: 'youtube.mediaCache.mode',
+      kind: 'enum',
+      enumValues: ['direct', 'background'],
+      enumLabels: {
+        direct: 'Direct stream extraction',
+        background: 'Background media cache',
+      },
+      defaultValue: defaultConfig.youtube.mediaCache.mode,
+      description: 'How YouTube card audio/images are extracted.',
+    },
+    {
+      path: 'youtube.mediaCache.maxHeight',
+      kind: 'number',
+      defaultValue: defaultConfig.youtube.mediaCache.maxHeight,
+      description:
+        'Maximum video height downloaded for the YouTube background media cache. Set to 0 for unlimited.',
+    },
     {
       path: 'controller.enabled',
       kind: 'boolean',

src/config/definitions/shared.ts

@@ -32,6 +32,7 @@ export interface ConfigOptionRegistryEntry {
    * `osd` and `osd-system` in NOTIFICATION_TYPE_VALUES.
    */
   enumValues?: readonly string[];
+  enumLabels?: Record<string, string>;
   /**
    * Optional settings UI subset when legacy/runtime-valid enum options should remain
    * editable in config files but hidden from new UI choices, for example