feat: edit API keys (name, rights); quick dump text above its buttons; inline note badges

- PATCH /keys/{id} renames a key or changes its scopes; the secret stays. Settings → API gets an
  edit button per key with the same switches as for a new key.
- Quick dump: a multiline text gets the full width, the buttons move to their own row below; the
  bar only goes back to one line once the text is clearly shorter (no flip-flopping).
- Notes: the "Erweitert"/"Unteraufgabe" badges sit right after the checkbox text.

v0.38.0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/lib/api.ts

@@ -1290,6 +1290,10 @@ export const api = {
     });
   },
 
+  async updateAPIKey(id: string, patch: { name?: string; scopes?: ApiKeyScope[] }): Promise<APIKey> {
+    return request<APIKey>(`/api/v1/keys/${id}`, { method: 'PATCH', body: JSON.stringify(patch) });
+  },
+
   async deleteAPIKey(id: string): Promise<void> {
     await request(`/api/v1/keys/${id}`, { method: 'DELETE' });
   },