web: account avatars, member /profile, framed admin panel

- an account can carry a picture: POST /api/auth/avatar (raw bytes,
  sniffed, replaces and unlinks the old file) and the public
  GET /api/users/:id/avatar. It rides wherever the account is named —
  the landing chip, the studio TopBar, the profile form.
- new /profile page for members, sharing one Profile form (picture,
  email, password) with the admin drawer.
- /admin is now one bordered frame whose left column is
  Profile / User account / Pictures / Close. Pictures lists every
  photo in the system with the slot that shows it; User account lists
  each account's name, email, picture and contribution count.
- account control opens a menu: Admin page + Log out for an admin,
  Profile + Log out for a member.

docker/frontend/src/main.tsx

@@ -8,12 +8,21 @@ import { I18nProvider } from './i18n/I18nProvider';
 import { Landing } from './Landing';
 import { Workspace } from './App';
 import { Admin } from './Admin';
+import { ProfilePage } from './ProfilePage';
 
-// Three routes, no router: the landing page, the workspace and the strip
-// moderation screen. nginx serves index.html for all of them (SPA fallback),
-// so this is just a pathname check.
+// Four routes, no router: the landing page, the workspace, the strip moderation
+// screen and the member's own profile. nginx serves index.html for all of them
+// (SPA fallback), so this is just a pathname check.
 const path = window.location.pathname;
-const page = path.startsWith('/app') ? <Workspace /> : path.startsWith('/admin') ? <Admin /> : <Landing />;
+const page = path.startsWith('/app') ? (
+  <Workspace />
+) : path.startsWith('/admin') ? (
+  <Admin />
+) : path.startsWith('/profile') ? (
+  <ProfilePage />
+) : (
+  <Landing />
+);
 const root = document.getElementById('root');
 if (!root) throw new Error('#root missing');