Migrate all IPC call sites to typed tauri-specta commands.*

Replace the remaining ~155 untyped invoke() calls across stores, services,
components, and routes with the generated commands.* wrappers from
$lib/api/bindings, so every IPC call is compile-time-checked against the
command signatures.

- Register repository_get_subtitle_url and repository_get_video_download_url
  in specta_builder() and the invoke_handler; regenerate bindings.ts.
- Source duplicated wire types (AutoplaySettings, CacheConfig, Session,
  ConnectivityStatus, audio/video settings, etc.) from bindings.
- Fix two bugs surfaced by the typed wrappers:
  - VideoDownloadButton passed an un-awaited Promise as the stream URL.
  - setAutoplaySettings omitted the required userId argument.
- Update unit tests asserting the old invoke(name, args) shape.
- Remove the five param-naming guard tests; the compiler and codegen now
  enforce what they checked.

svelte-check: 0 errors. vitest: green. cargo test --lib: green.

src/lib/api/bindings.ts

@@ -1121,6 +1121,18 @@ async repositoryGetItemsByPerson(handle: string, personId: string, options: GetI
 async repositoryGetSimilarItems(handle: string, itemId: string, limit: number | null) : Promise<SearchResult> {
     return await TAURI_INVOKE("repository_get_similar_items", { handle, itemId, limit });
 },
+/**
+ * Get subtitle URL for a media item
+ */
+async repositoryGetSubtitleUrl(handle: string, itemId: string, mediaSourceId: string, streamIndex: number, format: string) : Promise<string> {
+    return await TAURI_INVOKE("repository_get_subtitle_url", { handle, itemId, mediaSourceId, streamIndex, format });
+},
+/**
+ * Get video download URL with quality preset
+ */
+async repositoryGetVideoDownloadUrl(handle: string, itemId: string, quality: string, mediaSourceId: string | null) : Promise<string> {
+    return await TAURI_INVOKE("repository_get_video_download_url", { handle, itemId, quality, mediaSourceId });
+},
 /**
  * Create a new playlist
  */