Add upload type chooser and redesign upload modal

Clicking Create now opens a card-based chooser (Generic / Music / Sports)
before the upload modal; the chosen type is applied and its Content Type
dropdown is hidden as redundant.

Per type:
- Generic/Match show their fields inline in the modal (no card/popup);
  Music keeps the track-card + Track Editor popup for multi-language tracks.
- "Language Track" wording stays music-only; a single Language field is now
  available for generic/match too (mirrored on the mobile create page with
  name-swapping so only the active picker submits).

Also unifies all modal controls (dropdowns, selects, inputs) to one larger,
red-accented dark style scoped to #uploadModal.

Co-Authored-By: Claude Opus 4.7 <[email protected]>

resources/views/user/channel.blade.php

@@ -1386,7 +1386,7 @@ $headerSocialMap = [
                     <i class="bi bi-pencil"></i>
                     <span>Edit channel</span>
                 </button>
-                <button class="ch-btn-ghost" data-bs-toggle="modal" data-bs-target="#uploadModal">
+                <button class="ch-btn-ghost" onclick="openUploadChooser()">
                     <i class="bi bi-camera-video"></i>
                     <span>Upload</span>
                 </button>
@@ -1793,7 +1793,7 @@ $headerSocialMap = [
         <p>This channel hasn't uploaded any videos.</p>
         @auth
             @if(Auth::id() === $user->id)
-            <button class="ch-btn-primary" data-bs-toggle="modal" data-bs-target="#uploadModal">
+            <button class="ch-btn-primary" onclick="openUploadChooser()">
                 <i class="bi bi-cloud-upload"></i> Upload your first video
             </button>
             @endif