refactor(types): typed send helpers replace 16 as any casts (#210)

- sendRoomMessage (composer's fire-and-forget sends: text, location, voice,
  files, GIFs) and sendRoomEvent (polls, poll responses/ends, forwards,
  reactions, edits) in utils/room.ts carry the one cast each needs
  (`keyof TimelineEvents` / `RoomMessageEventContent`, no `any`).
- sendRoomMessage also swallows the rejected promise: a failed send already
  shows on the local echo (Failed to send + Retry, or the consent prompt), so
  it no longer surfaces as an unhandled error in the console.
- getAccountData narrows to `keyof AccountDataEvents`; ForwardMessageDialog's
  guard now narrows `contentToSend` itself (same behaviour).
- `as any` 39 → 23; eslint warnings 46 → 36, ratchet tightened to 36.

Verified in Chromium on a local Synapse: a text message, a quick reaction and
an edit all reach the server with the right content; a consent-blocked send
no longer logs an unhandled MatrixError. 1219 unit tests pass.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/features/room/PollCreator.tsx

@@ -21,6 +21,7 @@ import { Room } from 'matrix-js-sdk';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { stopPropagation } from '../../utils/keyboard';
 import { useModalStyle } from '../../hooks/useModalStyle';
+import { sendRoomEvent } from '../../utils/room';
 
 interface PollCreatorProps {
   roomId: string;
@@ -89,7 +90,7 @@ export function PollCreator({ roomId, threadRootId, onClose }: PollCreatorProps)
       );
       // Pass the thread id explicitly (like the sticker path in RoomInput); the
       // legacy 3-arg form always resolves to the main timeline.
-      await mx.sendEvent(roomId, threadRootId ?? null, 'm.poll.start' as any, {
+      await sendRoomEvent(mx, roomId, threadRootId ?? null, 'm.poll.start', {
         'm.poll': {
           question: { 'm.text': trimmedQuestion },
           answers: filledOptions.map((o, i) => ({ 'm.id': `${i}`, 'm.text': o })),