refactor(DP15): centralize sendStateEvent as-any cast in typed helper

Add a typed `sendStateEvent(mx, roomId, eventType, content, stateKey?)`
helper in utils/room.ts that mirrors the DP16 account-data helper pattern.
The SDK's typed `sendStateEvent` overload rejects the fork's custom
`StateEvent` enum values, so every call site cast arg 2 to `any` (which
also collapsed the content type). The single `as any` cast now lives inside
the helper; a generic `content: T extends object` keeps each call site's
content type checked.

Route all 32 `mx.sendStateEvent(..., StateEvent.X as any, ...)` casts across
20 files through the helper. The 2 dynamic-string casts in developer-tools
(SendRoomEvent, StateEventEditor) pass a runtime string, not an enum value,
so they stay as-is.

No behavior change.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/hooks/useCommands.ts

@@ -24,7 +24,7 @@ import {
 } from '../utils/matrix';
 import { useRoomNavigate } from './useRoomNavigate';
 import { Membership, StateEvent } from '../../types/matrix/room';
-import { getStateEvent } from '../utils/room';
+import { getStateEvent, sendStateEvent } from '../utils/room';
 import { splitWithSpace } from '../utils/common';
 import { createRoomEncryptionState } from '../components/create-room';
 
@@ -368,9 +368,10 @@ export const useCommands = (mx: MatrixClient, room: Room): CommandRecord => {
             ?.getStateEvents(StateEvent.RoomMember, mx.getSafeUserId());
           const content = mEvent?.getContent();
           if (!content) return;
-          await mx.sendStateEvent(
+          await sendStateEvent(
+            mx,
             room.roomId,
-            StateEvent.RoomMember as any,
+            StateEvent.RoomMember,
             {
               ...content,
               displayname: nick,
@@ -390,9 +391,10 @@ export const useCommands = (mx: MatrixClient, room: Room): CommandRecord => {
               ?.getStateEvents(StateEvent.RoomMember, mx.getSafeUserId());
             const content = mEvent?.getContent();
             if (!content) return;
-            await mx.sendStateEvent(
+            await sendStateEvent(
+              mx,
               room.roomId,
-              StateEvent.RoomMember as any,
+              StateEvent.RoomMember,
               {
                 ...content,
                 avatar_url: payload,
@@ -532,7 +534,7 @@ export const useCommands = (mx: MatrixClient, room: Room): CommandRecord => {
           aclContent.allow?.sort();
           aclContent.deny?.sort();
 
-          await mx.sendStateEvent(room.roomId, StateEvent.RoomServerAcl as any, aclContent);
+          await sendStateEvent(mx, room.roomId, StateEvent.RoomServerAcl, aclContent);
         },
       },
     }),