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-tauri/src/lib.rs

@@ -101,6 +101,7 @@ use commands::{
     repository_report_playback_start, repository_report_playback_progress, repository_report_playback_stopped,
     repository_get_image_url, repository_mark_favorite, repository_unmark_favorite,
     repository_get_person, repository_get_items_by_person, repository_get_similar_items,
+    repository_get_subtitle_url, repository_get_video_download_url,
     // Playlist commands
     playlist_create, playlist_delete, playlist_rename, playlist_get_items,
     playlist_add_items, playlist_remove_items, playlist_move_item,
@@ -565,6 +566,8 @@ fn specta_builder() -> Builder<tauri::Wry> {
             repository_get_person,
             repository_get_items_by_person,
             repository_get_similar_items,
+            repository_get_subtitle_url,
+            repository_get_video_download_url,
             // Playlist commands
             playlist_create,
             playlist_delete,