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/Http/Controllers/User/ProfileController.php

@@ -25,6 +25,7 @@ use Illuminate\Support\Facades\Schema;
 use Illuminate\View\View;
 use Illuminate\Support\Facades\Hash;
 use Illuminate\Validation\Rules\Password as PasswordRule;
+use Inertia\Inertia;
 
 class ProfileController extends Controller
 {
@@ -220,6 +221,10 @@ class ProfileController extends Controller
             $profileUpdates['friend_upload_notice'] = filter_var($validated['notify'], FILTER_VALIDATE_BOOLEAN) ? 1 : 0;
         }
 
+        if (array_key_exists('auto_post_upload', $validated)) {
+            $profileUpdates['auto_post_upload'] = filter_var($validated['auto_post_upload'], FILTER_VALIDATE_BOOLEAN) ? 1 : 0;
+        }
+
         if (isset($validated['signature'])) $profileUpdates['signature'] = $validated['signature'];
         if (isset($validated['description'])) $profileUpdates['description'] = $validated['description'];
 
@@ -498,24 +503,70 @@ class ProfileController extends Controller
             } catch (\Throwable) {}
         }
 
-        return response()->view('legacy::profile', [
-            'user'              => $user,
-            'profile'           => $profile,
-            'artworks'          => $artworks,
-            'featuredArtworks'  => $featuredArtworks,
-            'favourites'        => $favourites,
+        // ── Normalise artworks for JSON serialisation ────────────────────
+        $artworkItems = collect($artworks->items())->values();
+        $artworkPayload = [
+            'data'        => $artworkItems,
+            'next_cursor' => $artworks->nextCursor()?->encode(),
+            'has_more'    => $artworks->hasMorePages(),
+        ];
+
+        // ── Avatar URL on user object ────────────────────────────────────
+        $avatarUrl = AvatarUrl::forUser((int) $user->id, $user->profile?->avatar_hash, 128);
+
+        // ── Auth context for JS ───────────────────────────────────────────
+        $authData = null;
+        if (Auth::check()) {
+            /** @var \App\Models\User $authUser */
+            $authUser       = Auth::user();
+            $authAvatarUrl  = AvatarUrl::forUser((int) $authUser->id, $authUser->profile?->avatar_hash, 64);
+            $authData = [
+                'user' => [
+                    'id'       => $authUser->id,
+                    'username' => $authUser->username,
+                    'name'     => $authUser->name,
+                    'avatar'   => $authAvatarUrl,
+                ],
+            ];
+        }
+
+        $canonical = url('/@' . strtolower((string) ($user->username ?? '')));
+
+        return Inertia::render('Profile/ProfileShow', [
+            'user'              => [
+                'id'            => $user->id,
+                'username'      => $user->username,
+                'name'          => $user->name,
+                'avatar_url'    => $avatarUrl,
+                'created_at'    => $user->created_at?->toISOString(),
+                'last_visit_at' => $user->last_visit_at ? (string) $user->last_visit_at : null,
+            ],
+            'profile'           => $profile ? [
+                'about'        => $profile->about ?? null,
+                'website'      => $profile->website ?? null,
+                'country_code' => $profile->country_code ?? null,
+                'gender'       => $profile->gender ?? null,
+                'birthdate'    => $profile->birthdate ?? null,
+                'cover_image'  => $profile->cover_image ?? null,
+            ] : null,
+            'artworks'          => $artworkPayload,
+            'featuredArtworks'  => $featuredArtworks->values(),
+            'favourites'        => $favourites->values(),
             'stats'             => $stats,
             'socialLinks'       => $socialLinks,
             'followerCount'     => $followerCount,
-            'recentFollowers'   => $recentFollowers,
+            'recentFollowers'   => $recentFollowers->values(),
             'viewerIsFollowing' => $viewerIsFollowing,
             'heroBgUrl'         => $heroBgUrl,
-            'profileComments'   => $profileComments,
+            'profileComments'   => $profileComments->values(),
             'countryName'       => $countryName,
             'isOwner'           => $isOwner,
-            'page_title'        => 'Profile: ' . ($user->username ?? $user->name ?? ''),
-            'page_canonical'    => url('/@' . strtolower((string) ($user->username ?? ''))),
+            'auth'              => $authData,
+        ])->withViewData([
+            'page_title'            => ($user->username ?? $user->name ?? 'User') . ' on Skinbase',
+            'page_canonical'        => $canonical,
             'page_meta_description' => 'View the profile of ' . ($user->username ?? $user->name) . ' on Skinbase.org — artworks, favourites and more.',
+            'og_image'              => $avatarUrl,
         ]);
     }
 }