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/features/common-settings/emojis-stickers/RoomPacks.tsx

@@ -35,6 +35,7 @@ import { mxcUrlToHttp } from '../../../utils/matrix';
 import { useMediaAuthentication } from '../../../hooks/useMediaAuthentication';
 import { usePowerLevels } from '../../../hooks/usePowerLevels';
 import { StateEvent } from '../../../../types/matrix/room';
+import { sendStateEvent } from '../../../utils/room';
 import { suffixRename } from '../../../utils/common';
 import { AsyncStatus, useAsyncCallback } from '../../../hooks/useAsyncCallback';
 import { useAlive } from '../../../hooks/useAlive';
@@ -57,7 +58,7 @@ function CreatePackTile({ packs, roomId }: CreatePackTileProps) {
             display_name: name,
           },
         };
-        await mx.sendStateEvent(roomId, StateEvent.PoniesRoomEmotes as any, content, stateKey);
+        await sendStateEvent(mx, roomId, StateEvent.PoniesRoomEmotes, content, stateKey);
       },
       [mx, roomId],
     ),
@@ -164,7 +165,7 @@ export function RoomPacks({ onViewPack }: RoomPacksProps) {
       for (let i = 0; i < removedPacks.length; i += 1) {
         const addr = removedPacks[i];
         // eslint-disable-next-line no-await-in-loop
-        await mx.sendStateEvent(room.roomId, StateEvent.PoniesRoomEmotes as any, {}, addr.stateKey);
+        await sendStateEvent(mx, room.roomId, StateEvent.PoniesRoomEmotes, {}, addr.stateKey);
       }
     }, [mx, room, removedPacks]),
   );