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/layouts/partials/header.blade.php

@@ -28,7 +28,7 @@
         @auth
             <!-- Create / Upload -->
             <button type="button" class="yt-upload-btn d-none d-md-flex"
-                    data-bs-toggle="modal" data-bs-target="#uploadModal">
+                    onclick="openUploadChooser()">
                 <i class="bi bi-camera-video-fill"></i>
                 <span>Create</span>
             </button>