feat(channel): /@handle/{tab} aliases + cursor pagination on Videos tab

Two complementary additions that share the same bridge-not-rewrite
philosophy — reuse the existing single-page channel view instead of
splitting its 2000 lines into five route-driven partials.

/@handle/{tab}: videos / shorts / playlists / posts / about / wall
redirect to the equivalent /channel/{slug}#tab URL (302). The channel
page's existing hash-tab JS already handles landing on the right tab;
these aliases just make the URLs shareable in the YouTube style.

Channel Videos tab Load More: new JSON endpoint
GET /channel/{username}/videos/more returns the next cursor page of
server-rendered video cards. A sentinel + IntersectionObserver below
the grid fetches the next page when scrolled into view, with a Load
More button as fallback. Behavior mirrors the Phase 2 home feed —
users with thousands of uploads no longer get a 300-item grid on
first paint.

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

app/Http/Controllers/UserController.php

@@ -18,7 +18,7 @@ class UserController extends Controller
 {
     public function __construct()
     {
-        $this->middleware('auth')->except(['channel']);
+        $this->middleware('auth')->except(['channel', 'channelVideosMore']);
     }
 
     // Typeahead search for members (used by the "Share to member" picker)
@@ -372,6 +372,38 @@ class UserController extends Controller
         return redirect()->route('history')->with('toast_success', 'Watch history cleared.');
     }
 
+    /**
+     * JSON endpoint powering the "Load more" button on the channel Videos
+     * tab. Takes a username + optional cursor and returns a page of
+     * server-rendered video cards + next cursor. Reuses the cursorPaginate
+     * pattern Phase 2 established for the home feed.
+     */
+    public function channelVideosMore(Request $request, string $username)
+    {
+        $owner  = User::where('username', $username)->firstOrFail();
+        $viewer = Auth::user();
+        $isOwner = $viewer && $viewer->id === $owner->id;
+
+        $query = $isOwner
+            ? Video::where('user_id', $owner->id)
+            : Video::public()->where('user_id', $owner->id);
+
+        $paginator = $query->where('is_shorts', false)
+            ->latest('id')
+            ->cursorPaginate(24);
+
+        $html = '';
+        foreach ($paginator->items() as $video) {
+            $html .= view('components.video-card', ['video' => $video, 'hideChannelInfo' => true])->render();
+        }
+
+        return response()->json([
+            'items'       => $html,
+            'next_cursor' => optional($paginator->nextCursor())->encode(),
+            'has_more'    => $paginator->hasMorePages(),
+        ]);
+    }
+
     /**
      * Subscriptions feed — the public videos uploaded by every channel the
      * viewer is subscribed to, newest first. Replaces the dead href="#" that

resources/views/user/channel.blade.php

@@ -701,6 +701,56 @@ $headerSocialMap = [
             <span>No videos match your search</span>
         </div>
     </div>
+
+    {{-- Cursor-paginated Load More. The sentinel sits below the grid and
+         fetches the next slice when scrolled into view. A manual Load More
+         button is the fallback for browsers without IntersectionObserver. --}}
+    <div id="chVidSentinel"
+         data-username="{{ $user->username }}"
+         data-more-url="{{ route('channel.videos.more', ['username' => $user->username]) }}"
+         style="height:1px;"></div>
+    <div id="chVidLoadMoreWrap" style="display:none; text-align:center; padding:16px 0;">
+        <button type="button" id="chVidLoadMoreBtn" class="action-btn">Load more</button>
+    </div>
+    <script>
+    (function () {
+        const grid     = document.getElementById('chVidGrid');
+        const sentinel = document.getElementById('chVidSentinel');
+        const btnWrap  = document.getElementById('chVidLoadMoreWrap');
+        const btn      = document.getElementById('chVidLoadMoreBtn');
+        if (!grid || !sentinel) return;
+        let cursor = '', busy = false, done = false;
+        const url = sentinel.dataset.moreUrl;
+        async function loadMore() {
+            if (busy || done) return;
+            busy = true;
+            try {
+                const u = new URL(url, window.location.origin);
+                if (cursor) u.searchParams.set('cursor', cursor);
+                const r = await fetch(u.toString(), {
+                    headers: { 'X-Requested-With': 'XMLHttpRequest', 'Accept': 'application/json' },
+                    credentials: 'same-origin',
+                });
+                if (!r.ok) throw new Error('bad');
+                const d = await r.json();
+                if (d.items) grid.insertAdjacentHTML('beforeend', d.items);
+                cursor = d.next_cursor || '';
+                done   = !d.has_more;
+                if (done) { sentinel.style.display = 'none'; btnWrap.style.display = 'none'; }
+            } catch (e) {
+                btnWrap.style.display = 'block';
+            } finally { busy = false; }
+        }
+        btn?.addEventListener('click', loadMore);
+        if ('IntersectionObserver' in window) {
+            new IntersectionObserver(entries => {
+                if (entries.some(e => e.isIntersecting)) loadMore();
+            }, { rootMargin: '400px 0px' }).observe(sentinel);
+        } else {
+            btnWrap.style.display = 'block';
+        }
+    })();
+    </script>
     @else
     <div class="ch-empty">
         <div class="ch-empty-icon"><i class="bi bi-camera-video"></i></div>

routes/web.php

@@ -188,6 +188,8 @@ Route::middleware(['auth', 'verified'])->group(function () {
 
 // Channel - public for viewing. {username} is the user's slug (non-sequential, safe to share).
 Route::get('/channel/{username?}', [UserController::class, 'channel'])->name('channel');
+Route::get('/channel/{username}/videos/more', [UserController::class, 'channelVideosMore'])
+    ->name('channel.videos.more');
 // YouTube-style @handle alias. For now `handle` is just the existing
 // `username` slug — if the two ever diverge, flip the controller lookup
 // in UserController::channel() to prefer a dedicated `handle` column.
@@ -197,6 +199,20 @@ Route::get('/@{handle}', [UserController::class, 'channel'])
     ->where('handle', '[A-Za-z0-9][A-Za-z0-9._-]*')
     ->name('channel.handle');
 
+// Tab aliases: /@handle/videos lands on the Videos tab, /@handle/shorts on
+// Shorts, etc. These bridge to the single-page channel view by forwarding
+// the tab name as a hash — the channel.blade.php JS already handles
+// #wall/#videos/#shorts/#playlists/#about/#posts on load.
+Route::get('/@{handle}/{tab}', function (string $handle, string $tab) {
+    $allowed = ['wall', 'videos', 'shorts', 'playlists', 'posts', 'about'];
+    if (! in_array($tab, $allowed, true)) {
+        abort(404);
+    }
+    $user = \App\Models\User::where('username', $handle)->firstOrFail();
+    return redirect(route('channel', $user->channel) . '#' . $tab, 302);
+})->where(['handle' => '[A-Za-z0-9][A-Za-z0-9._-]*', 'tab' => '[a-z]+'])
+  ->name('channel.handle.tab');
+
 // Post routes - auth required
 Route::middleware(['auth'])->group(function () {
     Route::post('/channel/{user}/posts', [PostController::class, 'store'])->name('posts.store');