web: moderate accounts, accept 12MB uploads, put SAVE under CREATE

- /admin User account rows gain BLOCK/UNBLOCK, REMOVE/RESTORE and DELETE.
  Blocked = cannot sign in (sessions swept), removed = hidden from the strip
  and cannot sign in, both reversible; DELETE drops the account with its
  photos and recipes and unlinks the files. An allowlisted account is never
  a target, so an admin cannot moderate or delete itself.
- Photo uploads move from a 3MB API cap / 4m nginx cap to 12MB / 16m, and
  the browser shrinks an oversized still before sending it (2048px JPEG,
  avatars 512px) so the declared type still matches the sniffed bytes.
- The studio SAVE leaves the top bar and sits under the CREATE RECIPES tab,
  labelled SAVE RECIPES.

docker/frontend/src/ui/TopBar.tsx

@@ -14,7 +14,6 @@ export function TopBar({
   onUndo,
   onReset,
   onExport,
-  onSave,
   onAuth,
   onSignup,
   onLogout,
@@ -26,7 +25,6 @@ export function TopBar({
   onUndo: () => void;
   onReset: () => void;
   onExport: () => void;
-  onSave: () => void;
   onAuth: () => void;
   onSignup: () => void;
   onLogout: () => void;
@@ -57,7 +55,6 @@ export function TopBar({
 
       <button type="button" className="btn ghost" disabled={!canUndo} onClick={onUndo}>{t('act.undo')}</button>
       <button type="button" className="btn ghost" onClick={onReset}>{t('act.reset')}</button>
-      <button type="button" className="btn" onClick={onSave}>{t('save.save')}</button>
       <button type="button" className="btn primary" disabled={exporting} onClick={onExport}>
         {exporting ? t('act.exporting') : t('act.export')}
       </button>