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/autoplay.ts

@@ -4,28 +4,26 @@
  * Functions to control autoplay in the backend.
  */
 
-import { invoke } from "@tauri-apps/api/core";
+import { commands } from "$lib/api/bindings";
+import type { PlayItemRequest, AutoplaySettings } from "$lib/api/bindings";
+import { auth } from "$lib/stores/auth";
 
-export interface AutoplaySettings {
-  enabled: boolean;
-  countdownSeconds: number;
-  maxEpisodes: number;
-}
+export type { AutoplaySettings };
 
 export async function getAutoplaySettings(): Promise<AutoplaySettings> {
-  return invoke("player_get_autoplay_settings");
+  return commands.playerGetAutoplaySettings();
 }
 
 export async function setAutoplaySettings(
   settings: AutoplaySettings
 ): Promise<AutoplaySettings> {
-  return invoke("player_set_autoplay_settings", { settings });
+  return commands.playerSetAutoplaySettings(auth.getUserId() ?? "", settings);
 }
 
 export async function cancelAutoplayCountdown(): Promise<void> {
-  return invoke("player_cancel_autoplay_countdown");
+  await commands.playerCancelAutoplayCountdown();
 }
 
-export async function playNextEpisode(item: any): Promise<void> {
-  return invoke("player_play_next_episode", { item });
+export async function playNextEpisode(item: PlayItemRequest): Promise<void> {
+  await commands.playerPlayNextEpisode(item);
 }