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/routes/settings/+page.svelte

@@ -1,7 +1,8 @@
 <!-- TRACES: UR-023 | DR-048 -->
 <script lang="ts">
   import { onMount } from "svelte";
-  import { invoke } from "@tauri-apps/api/core";
+  import { commands } from "$lib/api/bindings";
+  import type { AudioSettings, VideoSettings, VolumeLevel } from "$lib/api/bindings";
   import {
     getCacheStats,
     setCacheLimit,
@@ -12,21 +13,6 @@
     type ImageCacheStats,
   } from "$lib/services/imageCache";
 
-  type VolumeLevel = "loud" | "normal" | "quiet";
-
-  interface AudioSettings {
-    crossfadeDuration: number;
-    gaplessPlayback: boolean;
-    normalizeVolume: boolean;
-    volumeLevel: VolumeLevel;
-  }
-
-  interface VideoSettings {
-    autoPlayNextEpisode: boolean;
-    autoPlayCountdownSeconds: number;
-    autoPlayMaxEpisodes: number;
-  }
-
   const episodeLimitOptions = [
     { value: 0, label: "Unlimited" },
     { value: 1, label: "1" },
@@ -75,8 +61,8 @@
     try {
       loading = true;
       const [audioResult, videoResult] = await Promise.all([
-        invoke<AudioSettings>("player_get_audio_settings"),
-        invoke<VideoSettings>("player_get_video_settings"),
+        commands.playerGetAudioSettings(),
+        commands.playerGetVideoSettings(),
       ]);
       settings = audioResult;
       videoSettings = videoResult;
@@ -142,8 +128,8 @@
       saving = true;
       saveMessage = "";
       await Promise.all([
-        invoke("player_set_audio_settings", { settings }),
-        invoke("player_set_video_settings", { settings: videoSettings }),
+        commands.playerSetAudioSettings(settings),
+        commands.playerSetVideoSettings(videoSettings),
       ]);
       saveMessage = "Settings saved successfully!";
       setTimeout(() => {