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/message/MessageEditor.tsx

@@ -21,7 +21,15 @@ import {
 } from 'folds';
 import { Editor, Transforms } from 'slate';
 import { ReactEditor } from 'slate-react';
-import { IContent, IMentions, MatrixEvent, MsgType, RelationType, Room } from 'matrix-js-sdk';
+import {
+  EventType,
+  IContent,
+  IMentions,
+  MatrixEvent,
+  MsgType,
+  RelationType,
+  Room,
+} from 'matrix-js-sdk';
 import { isKeyHotkey } from 'is-hotkey';
 import {
   AUTOCOMPLETE_PREFIXES,
@@ -55,6 +63,7 @@ import {
   getEditedEvent,
   getMemberName,
   getMentionContent,
+  sendRoomEvent,
   trimReplyFromFormattedBody,
 } from '../../../utils/room';
 import { mobileOrTablet } from '../../../utils/user-agent';
@@ -192,8 +201,7 @@ export const MessageEditor = as<'div', MessageEditorProps>(
               rel_type: RelationType.Replace,
             },
           };
-          // eslint-disable-next-line @typescript-eslint/no-explicit-any
-          return mx.sendMessage(roomId, content as any);
+          return sendRoomEvent(mx, roomId, null, EventType.RoomMessage, content);
         }
 
         const [prevBody, prevCustomHtml, prevMentions] = getPrevBodyAndFormattedBody();
@@ -241,8 +249,7 @@ export const MessageEditor = as<'div', MessageEditorProps>(
           },
         };
 
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        return mx.sendMessage(roomId, content as any);
+        return sendRoomEvent(mx, roomId, null, EventType.RoomMessage, content);
       }, [
         stripTracking,
         mx,