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/Pages/Profile/ProfileShow.jsx

@@ -0,0 +1,177 @@
+import React, { useState, useEffect, useCallback } from 'react'
+import { usePage } from '@inertiajs/react'
+import ProfileHero from '../../Components/Profile/ProfileHero'
+import ProfileStatsRow from '../../Components/Profile/ProfileStatsRow'
+import ProfileTabs from '../../Components/Profile/ProfileTabs'
+import TabArtworks from '../../Components/Profile/tabs/TabArtworks'
+import TabAbout from '../../Components/Profile/tabs/TabAbout'
+import TabStats from '../../Components/Profile/tabs/TabStats'
+import TabFavourites from '../../Components/Profile/tabs/TabFavourites'
+import TabCollections from '../../Components/Profile/tabs/TabCollections'
+import TabActivity from '../../Components/Profile/tabs/TabActivity'
+import TabPosts from '../../Components/Profile/tabs/TabPosts'
+
+const VALID_TABS = ['artworks', 'posts', 'collections', 'about', 'stats', 'favourites', 'activity']
+
+function getInitialTab() {
+  try {
+    const sp = new URLSearchParams(window.location.search)
+    const t = sp.get('tab')
+    return VALID_TABS.includes(t) ? t : 'artworks'
+  } catch {
+    return 'artworks'
+  }
+}
+
+/**
+ * ProfileShow – Inertia page for /@username
+ *
+ * Props injected by ProfileController::renderUserProfile()
+ */
+export default function ProfileShow() {
+  const { props } = usePage()
+
+  const {
+    user,
+    profile,
+    artworks,
+    featuredArtworks,
+    favourites,
+    stats,
+    socialLinks,
+    followerCount,
+    recentFollowers,
+    viewerIsFollowing,
+    heroBgUrl,
+    profileComments,
+    countryName,
+    isOwner,
+    auth,
+  } = props
+
+  const [activeTab, setActiveTab] = useState(getInitialTab)
+
+  const handleTabChange = useCallback((tab) => {
+    if (!VALID_TABS.includes(tab)) return
+    setActiveTab(tab)
+
+    // Update URL query param without full navigation
+    try {
+      const url = new URL(window.location.href)
+      if (tab === 'artworks') {
+        url.searchParams.delete('tab')
+      } else {
+        url.searchParams.set('tab', tab)
+      }
+      window.history.pushState({}, '', url.toString())
+    } catch (_) {}
+  }, [])
+
+  // Handle browser back/forward
+  useEffect(() => {
+    const onPop = () => setActiveTab(getInitialTab())
+    window.addEventListener('popstate', onPop)
+    return () => window.removeEventListener('popstate', onPop)
+  }, [])
+
+  const isLoggedIn = !!(auth?.user)
+
+  // Normalise artwork list  (SSR may send cursor-paginated object)
+  const artworkList = Array.isArray(artworks)
+    ? artworks
+    : (artworks?.data ?? [])
+  const artworkNextCursor = artworks?.next_cursor ?? null
+
+  // Normalise social links (may be object keyed by platform, or array)
+  const socialLinksObj = Array.isArray(socialLinks)
+    ? socialLinks.reduce((acc, l) => { acc[l.platform] = l; return acc }, {})
+    : (socialLinks ?? {})
+
+  return (
+    <div className="min-h-screen pb-16">
+      {/* Hero section */}
+      <ProfileHero
+        user={user}
+        profile={profile}
+        isOwner={isOwner}
+        viewerIsFollowing={viewerIsFollowing}
+        followerCount={followerCount}
+        heroBgUrl={heroBgUrl}
+        countryName={countryName}
+      />
+
+      {/* Stats pills row */}
+      <ProfileStatsRow
+        stats={stats}
+        followerCount={followerCount}
+        onTabChange={handleTabChange}
+      />
+
+      {/* Sticky tabs */}
+      <ProfileTabs
+        activeTab={activeTab}
+        onTabChange={handleTabChange}
+      />
+
+      {/* Tab content area */}
+      <div className="max-w-6xl mx-auto px-4">
+        {activeTab === 'artworks' && (
+          <TabArtworks
+            artworks={{ data: artworkList, next_cursor: artworkNextCursor }}
+            featuredArtworks={featuredArtworks}
+            username={user.username || user.name}
+            isActive
+          />
+        )}
+        {activeTab === 'posts' && (
+          <TabPosts
+            username={user.username || user.name}
+            isOwner={isOwner}
+            authUser={auth?.user ?? null}
+            user={user}
+            profile={profile}
+            stats={stats}
+            followerCount={followerCount}
+            recentFollowers={recentFollowers}
+            socialLinks={socialLinksObj}
+            countryName={countryName}
+            onTabChange={handleTabChange}
+          />
+        )}
+        {activeTab === 'collections' && (
+          <TabCollections collections={[]} />
+        )}
+        {activeTab === 'about' && (
+          <TabAbout
+            user={user}
+            profile={profile}
+            socialLinks={socialLinksObj}
+            countryName={countryName}
+            followerCount={followerCount}
+          />
+        )}
+        {activeTab === 'stats' && (
+          <TabStats
+            stats={stats}
+            followerCount={followerCount}
+          />
+        )}
+        {activeTab === 'favourites' && (
+          <TabFavourites
+            favourites={favourites}
+            isOwner={isOwner}
+            username={user.username || user.name}
+          />
+        )}
+        {activeTab === 'activity' && (
+          <TabActivity
+            profileComments={profileComments}
+            user={user}
+            isOwner={isOwner}
+            isLoggedIn={isLoggedIn}
+          />
+        )}
+      </div>
+    </div>
+  )
+}