refactor(episode): migrate episode upload to Livewire with real-time CDN verification

Replace the server-rendered episode upload form with a Livewire component,
introducing an interactive admin experience that validates the new episode's
stream path against all configured mirrors before saving. The controller-based
`store` method and its route are removed, and episode creation now flows
through the `AdminEpisodeForm` component with frontend upload handling and
dynamic quality checks.

Key changes:
- Add `AdminEpisodeForm` Livewire component with file uploads, tag handling,
  and debounced stream/base-url validation.
- Extend `CdnPathValidator::validateStream` to accept an episode number so the
  manifest path can point to the specific episode being added.
- Remove the `store` method from `EpisodeController` and its POST route.
- Delete the legacy `createEpisode` method from `EpisodeService`.
- Replace the Blade upload modal with the Livewire view, including progress
  indicators and validation badges.
- Add feature tests for the Livewire component and update unit tests for the
  CDN validator's episode-specific manifest check.

routes/admin.php

@@ -42,9 +42,6 @@ Route::group(['middleware' => ['auth', 'auth.admin']], function () {
     // Release
     Route::get('/admin/release', [ReleaseController::class, 'index'])->name('admin.upload.index');
 
-    // Episode
-    Route::post('/admin/episode/upload', [EpisodeController::class, 'store'])->name('admin.upload.episode');
-
     // Get Tags used for Upload Form
     Route::get('/admin/tags', [AdminApiController::class, 'getTags'])->name('admin.tags');
     Route::get('/admin/studios', [AdminApiController::class, 'getStudios'])->name('admin.studios');