feat(live): polish — ended-state, chat, viewer actions, Private option

Restores the live streaming controllers / views / model from the
pre-audit WIP that got stashed on 2026-10-21, then applies the Phase 6
polish items:

## /live/new form
Add a Private visibility option that mirrors the upload modal's
wording — "Only you can see this stream. Perfect for testing without
an audience." Validator in LiveStreamController@store now permits
public|unlisted|private (was public|unlisted).

## Watch page ended-state
When the stream status is "ended", the overlay is a solid "Stream
ended" card showing the stream's duration (started_at → ended_at)
and, when a recording was published, a Watch Replay CTA linking to
the saved video. Previously an ended stream showed the generic
"Waiting for the broadcast to start" placeholder forever.

## Channel name link
The uploader's name in the meta row is now a real <a href> to the
channel page.

## Viewer action row
Subscribe + Share buttons below the player, visible to anyone except
the owner. Subscribe for guests uses the Phase 7 ?intended= pattern
so after sign-in they land back on the stream.

## Live chat (DB-backed polling)
New live_chat_messages table (migration 2026_10_21_000003). Viewers
GET /live/{stream}/chat?since=N every 3 seconds; signed-in users POST
to the same path (rate-limited at 60/min). Guests see the panel in
read-only mode with a "Sign in to chat" placeholder.

Private streams reject chat for anyone but the owner (404). Non-live
status rejects chat sends (422). Author name is snapshotted at post
time so a renamed account's old messages keep the name they used.

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

app/Http/Controllers/LiveStreamController.php

@@ -0,0 +1,292 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\LiveChatMessage;
+use App\Models\LiveStream;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Auth;
+use Illuminate\Validation\Rule;
+
+/**
+ * Live streaming — broadcaster and viewer surfaces.
+ *
+ * The media plane (MediaMTX) is deliberately dumb: this controller decides who
+ * may broadcast, mints the short-lived credential the browser publishes with,
+ * and hands out the URLs. See LiveAuthController for the hook the media server
+ * calls back on.
+ */
+class LiveStreamController extends Controller
+{
+    public function __construct()
+    {
+        // Watching is open; everything that creates or controls a stream needs
+        // an account.
+        $this->middleware('auth')->except(['index', 'watch', 'status', 'chatPoll']);
+    }
+
+    /** Live now, plus the viewer's own streams when signed in. */
+    public function index(): \Illuminate\View\View
+    {
+        $live = LiveStream::live()
+            ->listed()
+            ->with('user')
+            ->latest('started_at')
+            ->limit(60)
+            ->get();
+
+        $mine = Auth::check()
+            ? LiveStream::where('user_id', Auth::id())->latest()->limit(20)->get()
+            : collect();
+
+        return view('live.index', compact('live', 'mine'));
+    }
+
+    /** The "start a broadcast" form. */
+    public function create(): \Illuminate\View\View
+    {
+        return view('live.create');
+    }
+
+    /**
+     * Create the stream record. This does NOT start anything — it reserves an
+     * identity and a path; the browser goes live from the broadcast page.
+     */
+    public function store(Request $request): \Illuminate\Http\RedirectResponse
+    {
+        $data = $request->validate([
+            'title' => ['required', 'string', 'max:120'],
+            'description' => ['nullable', 'string', 'max:2000'],
+            'visibility' => ['required', Rule::in(['public', 'unlisted', 'private'])],
+        ]);
+
+        // One live broadcast per account at a time. Without this a single user
+        // can pin open as many encoder slots as they can open tabs.
+        $alreadyLive = LiveStream::where('user_id', Auth::id())
+            ->where('status', LiveStream::STATUS_LIVE)
+            ->exists();
+
+        if ($alreadyLive) {
+            return back()
+                ->withInput()
+                ->withErrors(['title' => 'You already have a stream running. End it before starting another.']);
+        }
+
+        $stream = LiveStream::create([
+            'user_id' => Auth::id(),
+            'title' => $data['title'],
+            'description' => $data['description'] ?? null,
+            'visibility' => $data['visibility'],
+            'status' => LiveStream::STATUS_IDLE,
+        ]);
+
+        return redirect()->route('live.broadcast', $stream);
+    }
+
+    /** The broadcaster's camera page. Owner only. */
+    public function broadcast(LiveStream $stream): \Illuminate\View\View
+    {
+        abort_unless($stream->isOwnedBy(Auth::user()), 403);
+
+        // An ended stream is not a dead one — the owner may go live on it
+        // again from the same link.
+        $stream->reArm();
+
+        return view('live.broadcast', [
+            'stream' => $stream,
+            'whipUrl' => $this->whipUrl($stream),
+            'watchUrl' => route('live.watch', $stream),
+            'iceServers' => $this->iceServers(),
+        ]);
+    }
+
+    /**
+     * Mint the publish credential.
+     *
+     * Separate from the page load so the token's short life starts when the
+     * user actually presses "Go live", not when they opened the tab and went
+     * to find a tripod.
+     */
+    public function token(LiveStream $stream): JsonResponse
+    {
+        abort_unless($stream->isOwnedBy(Auth::user()), 403);
+
+        // Pressing "Go live" on a stream that previously ended restarts it
+        // rather than being refused. A failed attempt must never burn the link.
+        $stream->reArm();
+
+        return response()->json([
+            'token' => $stream->issuePublishToken(),
+            'expires_in' => LiveStream::PUBLISH_TOKEN_TTL_SECONDS,
+            'whip_url' => $this->whipUrl($stream),
+            'ice_servers' => $this->iceServers(),
+        ]);
+    }
+
+    /** The viewer page. */
+    public function watch(LiveStream $stream): \Illuminate\View\View
+    {
+        abort_unless($stream->isWatchableBy(Auth::user()), 404);
+
+        $stream->loadMissing('user');
+
+        return view('live.watch', [
+            'stream' => $stream,
+            'whepUrl' => $this->whepUrl($stream),
+            'hlsUrl' => $this->hlsUrl($stream),
+            'isOwner' => $stream->isOwnedBy(Auth::user()),
+            'iceServers' => $this->iceServers(),
+        ]);
+    }
+
+    /** Lightweight poll for the viewer page: is it live, how many watching. */
+    public function status(LiveStream $stream): JsonResponse
+    {
+        abort_unless($stream->isWatchableBy(Auth::user()), 404);
+
+        return response()->json([
+            'status' => $stream->status,
+            'live' => $stream->isLive(),
+            'viewers' => $stream->current_viewers,
+            'duration' => $stream->formatted_duration,
+        ]);
+    }
+
+    /** End the broadcast. Owner only. */
+    public function stop(LiveStream $stream): JsonResponse
+    {
+        abort_unless($stream->isOwnedBy(Auth::user()), 403);
+
+        $stream->markEnded();
+
+        return response()->json([
+            'success' => true,
+            'status' => $stream->status,
+            'duration' => $stream->formatted_duration,
+        ]);
+    }
+
+    /* ---------------- URLs ---------------- */
+
+    /*
+     * These are same-origin paths, proxied by nginx to the media server on
+     * loopback. Same-origin matters: the page is served over HTTPS, and a
+     * mixed-content or cross-origin media URL would be blocked by the browser
+     * before WebRTC ever started.
+     */
+
+    private function whipUrl(LiveStream $stream): string
+    {
+        return url('/live-rtc/'.$stream->mediaPath().'/whip');
+    }
+
+    private function whepUrl(LiveStream $stream): string
+    {
+        return url('/live-rtc/'.$stream->mediaPath().'/whep');
+    }
+
+    private function hlsUrl(LiveStream $stream): string
+    {
+        return url('/live-hls/'.$stream->mediaPath().'/index.m3u8');
+    }
+
+    /**
+     * ICE servers for the browser.
+     *
+     * No inbound UDP port is forwarded to this server, so a broadcaster outside
+     * the local network can only reach it through a TURN relay. On the LAN the
+     * host candidates work directly and TURN is never used.
+     *
+     * Configured through the environment so credentials never sit in the repo.
+     */
+    private function iceServers(): array
+    {
+        $servers = [];
+
+        if ($stun = config('live.stun_url')) {
+            $servers[] = ['urls' => $stun];
+        }
+
+        if ($turn = config('live.turn_url')) {
+            $servers[] = array_filter([
+                'urls' => $turn,
+                'username' => config('live.turn_username'),
+                'credential' => config('live.turn_credential'),
+            ]);
+        }
+
+        return $servers;
+    }
+
+    /**
+     * GET poll: viewer asks for every message in this stream newer than
+     * ?since=<id> (defaults to 0 for a cold open). Returns up to 50
+     * messages — more than enough for a 3-second polling window, bounded
+     * to protect the DB when a client is slow to reconnect.
+     */
+    public function chatPoll(Request $request, LiveStream $stream): JsonResponse
+    {
+        // Private streams are owner-only; everything else is open to viewers.
+        if ($stream->visibility === 'private' && Auth::id() !== $stream->user_id) {
+            abort(404);
+        }
+
+        $since = (int) $request->query('since', 0);
+        $rows  = LiveChatMessage::where('livestream_id', $stream->id)
+            ->where('id', '>', $since)
+            ->orderBy('id')
+            ->limit(50)
+            ->get(['id', 'user_id', 'author_name', 'body', 'created_at']);
+
+        return response()->json([
+            'messages' => $rows->map(fn ($m) => [
+                'id'   => $m->id,
+                'uid'  => $m->user_id,
+                'name' => $m->author_name,
+                'body' => $m->body,
+                'at'   => $m->created_at?->toISOString(),
+            ])->all(),
+        ]);
+    }
+
+    /**
+     * POST a chat message. Rate-limited to roughly one message per second
+     * per user via Laravel's built-in throttle, applied via the route.
+     * Body is capped at 400 chars (long enough for a sentence, short enough
+     * that the panel doesn't shear into a wall of text).
+     */
+    public function chatSend(Request $request, LiveStream $stream): JsonResponse
+    {
+        if ($stream->status !== LiveStream::STATUS_LIVE) {
+            return response()->json(['error' => 'Chat is closed when the stream isn\'t live.'], 422);
+        }
+        if ($stream->visibility === 'private' && Auth::id() !== $stream->user_id) {
+            abort(404);
+        }
+
+        $data = $request->validate([
+            'body' => ['required', 'string', 'max:400'],
+        ]);
+
+        $user = Auth::user();
+        $msg  = LiveChatMessage::create([
+            'livestream_id' => $stream->id,
+            'user_id'       => $user->id,
+            'author_name'   => $user->name,
+            'body'          => trim($data['body']),
+            'created_at'    => now(),
+        ]);
+
+        return response()->json([
+            'ok' => true,
+            'message' => [
+                'id'   => $msg->id,
+                'uid'  => $msg->user_id,
+                'name' => $msg->author_name,
+                'body' => $msg->body,
+                'at'   => $msg->created_at?->toISOString(),
+            ],
+        ]);
+    }
+}