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/entry-forum.jsx

@@ -0,0 +1,37 @@
+/**
+ * Forum React Island Entry Point
+ *
+ * Auto-detects which forum page mount-point is present in the DOM
+ * and renders the corresponding React component with server-provided props.
+ */
+
+import React from 'react'
+import { createRoot } from 'react-dom/client'
+
+const MOUNTS = [
+  { rootId: 'forum-index-root',       propsId: 'forum-index-props',       loader: () => import('./Pages/Forum/ForumIndex') },
+  { rootId: 'forum-category-root',    propsId: 'forum-category-props',    loader: () => import('./Pages/Forum/ForumCategory') },
+  { rootId: 'forum-thread-root',      propsId: 'forum-thread-props',      loader: () => import('./Pages/Forum/ForumThread') },
+  { rootId: 'forum-new-thread-root',  propsId: 'forum-new-thread-props',  loader: () => import('./Pages/Forum/ForumNewThread') },
+  { rootId: 'forum-edit-post-root',   propsId: 'forum-edit-post-props',   loader: () => import('./Pages/Forum/ForumEditPost') },
+]
+
+for (const { rootId, propsId, loader } of MOUNTS) {
+  const el = document.getElementById(rootId)
+  if (!el) continue
+
+  let props = {}
+  try {
+    const propsEl = document.getElementById(propsId)
+    props = propsEl ? JSON.parse(propsEl.textContent || '{}') : {}
+  } catch {
+    props = {}
+  }
+
+  loader().then((mod) => {
+    const Component = mod.default
+    createRoot(el).render(<Component {...props} />)
+  })
+
+  break // Only one forum page per request
+}