feat: member portal Sprint 1 — dashboard with MemberShell layout and TowerUser profile fields

- Add avatar, hometown, currentLocation, interests, language, digestPreference, directoryVisible fields to TowerUser
- Migration: 20260617200000_add_tower_user_profile_fields
- GET /my/dashboard API endpoint with stats (groups, messages, consents)
- BFF route /api/my/dashboard
- MemberShell 3-column layout (220px nav + flex-1 main + 280px rail)
- Dashboard page: hero card, stat cards, group list, interests chips
- Sidebar returns null for /my paths (MemberShell owns the nav)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/app/_lib/sidebar.tsx

@@ -85,25 +85,7 @@ export function Sidebar() {
   }
 
   if (MEMBER_PATHS.some((p) => pathname.startsWith(p))) {
-    return (
-      <nav className="w-52 shrink-0 bg-white border-r border-gray-200 p-4 flex flex-col">
-        <span className="font-bold text-base mb-4">TOWER</span>
-        <div className="flex flex-col gap-1 flex-1">
-          <Link href="/my" className="rounded px-3 py-2 text-sm hover:bg-gray-100">
-            Profile
-          </Link>
-          <Link href="/my/groups" className="rounded px-3 py-2 text-sm hover:bg-gray-100">
-            Groups
-          </Link>
-          <Link href="/my/settings" className="rounded px-3 py-2 text-sm hover:bg-gray-100">
-            Settings
-          </Link>
-        </div>
-        <div className="border-t border-gray-200 pt-3 mt-3 text-xs text-gray-500 px-3">
-          Member portal
-        </div>
-      </nav>
-    );
+    return null;
   }
 
   return (