chore(types): fewer any casts; eslint warning ratchet 36 -> 29 (#210)

- Developer tools (send event, state event editor, room account data) and
  setMarkedUnread go through the typed helpers in utils/room and
  utils/accountData (new setRoomAccountData) instead of casting at the
  call site; sendStateEvent accepts a developer-chosen type string.
- SecretStorage passes the key description as the SDK's
  SecretStorageKeyDescription, CallEmbed replies with an IWidgetApiRequest,
  and fillMissingPowers writes through a Record instead of `as any`.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/features/common-settings/developer-tools/DevelopTools.tsx

@@ -30,6 +30,7 @@ import {
   AccountDataSubmitCallback,
 } from '../../../components/AccountDataEditor';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
+import { setRoomAccountData } from '../../../utils/accountData';
 
 type DeveloperToolsProps = {
   requestClose: () => void;
@@ -58,8 +59,7 @@ export function DeveloperTools({ requestClose }: DeveloperToolsProps) {
 
   const submitAccountData: AccountDataSubmitCallback = useCallback(
     async (type, content) => {
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      await mx.setRoomAccountData(room.roomId, type as any, content);
+      await setRoomAccountData(mx, room.roomId, type, content);
     },
     [mx, room.roomId],
   );