feat(watch): match channel row, read-more clamp, nested-reply @prefill

Match page: the only path from a match video to the uploader's channel
was a tiny avatar buried inside the Match Overview card. Add the shared
<x-channel-row :video> component right under the title + action bar so
the Subscribe + channel link is as prominent as it is on music and
generic pages.

Comments:
- Long comments collapse to a 4-line clamp with a "Read more" / "Show
  less" toggle. The CSS line-clamp doesn't cut mid-word, and the
  button is added after enhanceBody() runs so it measures the final
  rendered height (timestamps + mentions already materialised).
- Nested-reply Reply button: each reply now carries a button that
  opens the parent-level reply form and prefills "@AuthorName " so
  the thread stays readable even though the DB only stores one-level
  nesting.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

resources/views/videos/types/match.blade.php

@@ -2418,6 +2418,13 @@
             </div>
             <!-- ===== END EVENT HEADER ===== -->
 
+            {{-- Channel row — the generic + music watch pages render this
+                 just under the title. The match page used to omit it so
+                 the only way to reach the uploader's channel from a match
+                 video was the small avatar hidden inside the Match Overview
+                 section. --}}
+            <x-channel-row :video="$video" />
+
             @include('videos.partials.description-box', ['video' => $video])
 
             {{-- ---- legacy match description panel (kept for reference, hidden) ---- --}}