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>

internal/api/handlers_integrations.go

@@ -42,6 +42,29 @@ func (s *Server) handleCreateAPIKey(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusCreated, key)
 }
 
+// handleUpdateAPIKey renames a key or changes its rights; the key itself stays the same.
+func (s *Server) handleUpdateAPIKey(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r.Context())
+	var req struct {
+		Name   *string   `json:"name"`
+		Scopes *[]string `json:"scopes"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "Ungültiges JSON")
+		return
+	}
+	key, err := s.store.UpdateAPIKey(userID, chi.URLParam(r, "id"), req.Name, req.Scopes)
+	if errors.Is(err, storage.ErrAPIKeyNotFound) {
+		writeError(w, http.StatusNotFound, err.Error())
+		return
+	}
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, key)
+}
+
 func (s *Server) handleDeleteAPIKey(w http.ResponseWriter, r *http.Request) {
 	userID := auth.GetUserID(r.Context())
 	keyID := chi.URLParam(r, "id")