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

resources/js/components/forum/CategoryCard.jsx

@@ -0,0 +1,85 @@
+import React from 'react'
+
+export default function CategoryCard({ category }) {
+  const name          = category?.name ?? 'Untitled'
+  const slug          = category?.slug
+  const threads       = category?.thread_count ?? 0
+  const posts         = category?.post_count ?? 0
+  const lastActivity  = category?.last_activity_at
+  const preview       = category?.preview_image ?? '/images/forum-default.jpg'
+  const href          = slug ? `/forum/${slug}` : '#'
+
+  const timeAgo = lastActivity ? formatTimeAgo(lastActivity) : null
+
+  return (
+    <a
+      href={href}
+      className="group relative block overflow-hidden rounded-2xl border border-white/[0.06] bg-nova-800/50 shadow-xl backdrop-blur transition-all duration-300 hover:border-cyan-400/20 hover:shadow-cyan-500/10 focus:outline-none focus-visible:ring-2 focus-visible:ring-cyan-400"
+    >
+      {/* Image */}
+      <div className="relative aspect-[16/9]">
+        <img
+          src={preview}
+          alt={`${name} preview`}
+          loading="lazy"
+          decoding="async"
+          className="h-full w-full object-cover object-center transition-transform duration-500 group-hover:scale-[1.03]"
+        />
+        <div className="absolute inset-0 bg-gradient-to-t from-black/80 via-black/30 to-transparent" />
+
+        {/* Overlay content */}
+        <div className="absolute inset-x-0 bottom-0 p-5">
+          <div className="mb-2 inline-flex h-8 w-8 items-center justify-center rounded-lg bg-cyan-400/15 text-cyan-300">
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <path d="M21 15a2 2 0 01-2 2H7l-4 4V5a2 2 0 012-2h14a2 2 0 012 2z" />
+            </svg>
+          </div>
+
+          <h3 className="text-lg font-bold text-white leading-snug">{name}</h3>
+
+          {timeAgo && (
+            <p className="mt-1 text-xs text-white/50">
+              Last activity: <span className="text-white/70">{timeAgo}</span>
+            </p>
+          )}
+
+          <div className="mt-3 flex items-center gap-4 text-sm">
+            <span className="flex items-center gap-1.5 text-cyan-300">
+              <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+                <path d="M21 15a2 2 0 01-2 2H7l-4 4V5a2 2 0 012-2h14a2 2 0 012 2z" />
+              </svg>
+              {number(posts)} posts
+            </span>
+            <span className="flex items-center gap-1.5 text-cyan-300/70">
+              <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+                <path d="M14 2H6a2 2 0 00-2 2v16a2 2 0 002 2h12a2 2 0 002-2V8z" />
+                <polyline points="14 2 14 8 20 8" />
+              </svg>
+              {number(threads)} topics
+            </span>
+          </div>
+        </div>
+      </div>
+    </a>
+  )
+}
+
+function number(n) {
+  return (n ?? 0).toLocaleString()
+}
+
+function formatTimeAgo(dateStr) {
+  try {
+    const date = new Date(dateStr)
+    const now  = new Date()
+    const diff = Math.floor((now - date) / 1000)
+
+    if (diff < 60)    return 'just now'
+    if (diff < 3600)  return `${Math.floor(diff / 60)}m ago`
+    if (diff < 86400) return `${Math.floor(diff / 3600)}h ago`
+    if (diff < 604800) return `${Math.floor(diff / 86400)}d ago`
+    return date.toLocaleDateString('en-GB', { day: '2-digit', month: '2-digit', year: 'numeric' })
+  } catch {
+    return null
+  }
+}