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.test.ts

@@ -10,6 +10,7 @@ import {
   playNextEpisode,
   type AutoplaySettings,
 } from "./autoplay";
+import type { PlayItemRequest } from "./bindings";
 
 vi.mock("@tauri-apps/api/core", () => ({
   invoke: vi.fn(async (command: string, args?: any) => {
@@ -33,6 +34,23 @@ vi.mock("@tauri-apps/api/core", () => ({
   }),
 }));
 
+// setAutoplaySettings sources the user id from the auth store
+vi.mock("$lib/stores/auth", () => ({
+  auth: { getUserId: () => "user-1" },
+}));
+
+// Minimal valid PlayItemRequest for playNextEpisode tests
+function makeItem(overrides: Partial<PlayItemRequest> = {}): PlayItemRequest {
+  return {
+    id: "item-123",
+    title: "Episode 1",
+    streamUrl: "http://example/stream",
+    videoCodec: "h264",
+    needsTranscoding: false,
+    ...overrides,
+  };
+}
+
 describe("autoplay API", () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -98,7 +116,7 @@ describe("autoplay API", () => {
         (c) => c[0] === "player_set_autoplay_settings"
       );
       expect(call).toBeDefined();
-      expect(call![1]).toEqual({ settings });
+      expect(call![1]).toEqual({ userId: "user-1", settings });
     });
 
     it("should support different countdown values", async () => {
@@ -130,11 +148,7 @@ describe("autoplay API", () => {
 
   describe("playNextEpisode", () => {
     it("should play next episode with item", async () => {
-      const mockItem = {
-        id: "item-123",
-        name: "Episode 1",
-        seriesId: "series-456",
-      };
+      const mockItem = makeItem();
 
       await playNextEpisode(mockItem);
 
@@ -150,9 +164,9 @@ describe("autoplay API", () => {
 
     it("should handle different item types", async () => {
       const items = [
-        { id: "1", name: "Episode 1" },
-        { id: "2", name: "Episode 2", seasonNumber: 1 },
-        { id: "3", name: "Episode 3", episodeNumber: 5 },
+        makeItem({ id: "1", title: "Episode 1" }),
+        makeItem({ id: "2", title: "Episode 2" }),
+        makeItem({ id: "3", title: "Episode 3" }),
       ];
 
       for (const item of items) {