feat: forum rich-text editor, emoji picker, mentions, discover nav, feed, uploads, profile

Forum:
- TipTap WYSIWYG editor with full toolbar
- @emoji-mart/react emoji picker (consistent with tweets)
- @mention autocomplete with user search API
- Fix PHP 8.4 parse errors in Blade templates
- Fix thread data display (paginator items)
- Align forum page widths to max-w-5xl

Discover:
- Extract shared _nav.blade.php partial
- Add missing nav links to for-you page
- Add Following link for authenticated users

Feed/Posts:
- Post model, controllers, policies, migrations
- Feed page components (PostComposer, FeedCard, etc)
- Post reactions, comments, saves, reports, sharing
- Scheduled publishing support
- Link preview controller

Profile:
- Profile page components (ProfileHero, ProfileTabs)
- Profile API controller

Uploads:
- Upload wizard enhancements
- Scheduled publish picker
- Studio status bar and readiness checklist

app/Console/Commands/PublishScheduledPostsCommand.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace App\Console\Commands;
+
+use App\Models\Post;
+use Illuminate\Console\Command;
+use Illuminate\Support\Facades\DB;
+
+/**
+ * Publishes posts whose publish_at timestamp has passed.
+ * Scheduled every minute via console/kernel.
+ */
+class PublishScheduledPostsCommand extends Command
+{
+    protected $signature   = 'posts:publish-scheduled';
+    protected $description = 'Publish all scheduled posts whose publish_at time has been reached.';
+
+    public function handle(): int
+    {
+        $count = Post::where('status', Post::STATUS_SCHEDULED)
+            ->where('publish_at', '<=', now())
+            ->count();
+
+        if ($count === 0) {
+            $this->line('No scheduled posts to publish.');
+            return self::SUCCESS;
+        }
+
+        $published = 0;
+
+        Post::where('status', Post::STATUS_SCHEDULED)
+            ->where('publish_at', '<=', now())
+            ->chunkById(100, function ($posts) use (&$published) {
+                foreach ($posts as $post) {
+                    DB::transaction(function () use ($post) {
+                        $post->update(['status' => Post::STATUS_PUBLISHED]);
+                    });
+                    $published++;
+                }
+            });
+
+        $this->info("Published {$published} scheduled post(s).");
+
+        return self::SUCCESS;
+    }
+}