Add Shared Media drawer and harden same-room navigation.

Widen the media panel, support skinny full-page mode, keep jump-to-latest and return-to-previous reliable, and stop same-room event jumps from remounting the outlet or yanking the sidebar.

src/app/pages/paths.ts

@@ -54,6 +54,7 @@ export type DirectCreateSearchParams = {
   userId?: string;
 };
 export const DIRECT_CREATE_PATH = `/direct/${_CREATE_PATH}`;
+export const DIRECT_SEARCH_PATH = `/direct/${_SEARCH_PATH}`;
 export const DIRECT_ROOM_PATH = `/direct/${_ROOM_PATH}`;
 
 export const SPACE_PATH = '/:spaceIdOrAlias/';