feat(channels): route room-in-space navigations through /channels/ with eventId-anchored permalinks and channels-aware cold-push redirect

src/app/hooks/useRoomNavigate.ts

@@ -2,7 +2,7 @@ import { useCallback, useRef } from 'react';
 import { NavigateOptions, useLocation, useNavigate } from 'react-router-dom';
 import { useAtomValue } from 'jotai';
 import { getCanonicalAliasOrRoomId } from '../utils/matrix';
-import { getDirectRoomPath, getSpacePath, getSpaceRoomPath } from '../pages/pathUtils';
+import { getChannelsRoomPath, getDirectRoomPath, getSpacePath } from '../pages/pathUtils';
 import { useMatrixClient } from './useMatrixClient';
 import { getOrphanParents, guessPerfectParent, isSpace } from '../utils/room';
 import { roomToParentsAtom } from '../state/room/roomToParents';
@@ -61,9 +61,18 @@ export const useRoomNavigate = () => {
   const navigateRoom = useCallback(
     (roomId: string, eventId?: string, opts?: NavigateOptions) => {
       const roomIdOrAlias = getCanonicalAliasOrRoomId(mx, roomId);
-      const openSpaceTimeline = developerTools && spaceSelectedId === roomId;
 
-      const orphanParents = openSpaceTimeline ? [roomId] : getOrphanParents(roomToParents, roomId);
+      // Developer-tools edge case: clicking the rail-selected space row
+      // opens the space's own timeline as a pseudo-room. Route through
+      // /channels/<space>/<space>/ so the dev view shares the channels
+      // SpaceRouteRoomProvider — its `developerTools && isSpaceRoom &&
+      // room.roomId === space.roomId` branch already permits this.
+      if (developerTools && spaceSelectedId === roomId) {
+        safeNavigate(getChannelsRoomPath(roomIdOrAlias, roomIdOrAlias, eventId), opts);
+        return;
+      }
+
+      const orphanParents = getOrphanParents(roomToParents, roomId);
       if (orphanParents.length > 0) {
         let parentSpace: string;
         if (spaceSelectedId && orphanParents.includes(spaceSelectedId)) {
@@ -74,10 +83,7 @@ export const useRoomNavigate = () => {
 
         const pSpaceIdOrAlias = getCanonicalAliasOrRoomId(mx, parentSpace);
 
-        safeNavigate(
-          getSpaceRoomPath(pSpaceIdOrAlias, openSpaceTimeline ? roomId : roomIdOrAlias, eventId),
-          opts
-        );
+        safeNavigate(getChannelsRoomPath(pSpaceIdOrAlias, roomIdOrAlias, eventId), opts);
         return;
       }
 

src/app/pages/Router.tsx

@@ -15,6 +15,7 @@ import { AuthLayout, Login, Register, ResetPassword } from './auth';
 import {
   BOTS_PATH,
   CHANNELS_PATH,
+  CHANNELS_ROOM_EVENT_PATH,
   CHANNELS_ROOM_PATH,
   CHANNELS_SPACE_PATH,
   CHANNELS_THREAD_PATH,
@@ -323,6 +324,10 @@ export const createRouter = (clientConfig: ClientConfig, screenSize: ScreenSize)
                   SpaceRouteRoomProvider lives on the parent route and
                   stays mounted across the room↔thread URL flip. */}
               <Route path={CHANNELS_THREAD_PATH.slice(CHANNELS_ROOM_PATH.length)} element={null} />
+              {/* Event-anchored URL — search/inbox/mention/push permalinks.
+                  RR6 merges child params into the parent's useParams so
+                  Room.tsx reads `eventId` without re-routing. */}
+              <Route path={CHANNELS_ROOM_EVENT_PATH.slice(CHANNELS_ROOM_PATH.length)} element={null} />
             </Route>
           </Route>
         </Route>

src/app/pages/client/home/RoomProvider.tsx

@@ -6,9 +6,10 @@ import { useMatrixClient } from '../../../hooks/useMatrixClient';
 import { JoinBeforeNavigate } from '../../../features/join-before-navigate';
 import { useSearchParamsViaServers } from '../../../hooks/router/useSearchParamsViaServers';
 import { allRoomsAtom } from '../../../state/room-list/roomList';
-import { getDirectRoomPath } from '../../pathUtils';
+import { roomToParentsAtom } from '../../../state/room/roomToParents';
+import { getChannelsRoomPath, getDirectRoomPath } from '../../pathUtils';
 import { getCanonicalAliasOrRoomId } from '../../../utils/matrix';
-import { isSpace } from '../../../utils/room';
+import { getOrphanParents, guessPerfectParent, isSpace } from '../../../utils/room';
 
 export function HomeRouteRoomProvider({ children: _children }: { children: ReactNode }) {
   const mx = useMatrixClient();
@@ -23,17 +24,32 @@ export function HomeRouteRoomProvider({ children: _children }: { children: React
   // explicitly so the redirect re-evaluates after /sync. See plan §6.7 / §6.8
   // / round-5 review notes.
   useAtomValue(allRoomsAtom);
+  // Subscribe roomToParentsAtom so the channels-vs-direct branch re-evaluates
+  // after /sync populates the m.space.parent / m.space.child mappings. Without
+  // this subscription a cold push for a room-in-space would render once with
+  // an empty parents map and miss the channels redirect.
+  const roomToParents = useAtomValue(roomToParentsAtom);
 
   const { roomIdOrAlias, eventId } = useParams();
   const viaServers = useSearchParamsViaServers();
   const roomId = useSelectedRoom();
   const room = mx.getRoom(roomId);
 
-  // After P3c the Home tab is gone — every non-space room redirects to the
-  // unified Direct list. /home/{roomId}/ stays as a deep-link compatibility
-  // shim for cold-start push (sw.ts cannot read mDirectAtom).
+  // After P3c the Home tab is gone — /home/{roomId}/ stays as a deep-link
+  // compatibility shim for cold-start push (sw.ts cannot read mDirectAtom or
+  // roomToParentsAtom). Room-in-space rooms route into /channels/, everything
+  // else falls through to the universal /direct/ list.
   if (room && !isSpace(room)) {
     const alias = getCanonicalAliasOrRoomId(mx, room.roomId);
+    const orphanParents = getOrphanParents(roomToParents, room.roomId);
+    if (orphanParents.length > 0) {
+      const parentSpace =
+        guessPerfectParent(mx, room.roomId, orphanParents) ?? orphanParents[0];
+      const pSpaceIdOrAlias = getCanonicalAliasOrRoomId(mx, parentSpace);
+      return (
+        <Navigate to={getChannelsRoomPath(pSpaceIdOrAlias, alias, eventId)} replace />
+      );
+    }
     return <Navigate to={getDirectRoomPath(alias, eventId)} replace />;
   }
 

src/app/pages/pathUtils.ts

@@ -3,6 +3,7 @@ import {
   BOTS_BOT_PATH,
   BOTS_PATH,
   CHANNELS_PATH,
+  CHANNELS_ROOM_EVENT_PATH,
   CHANNELS_ROOM_PATH,
   CHANNELS_SPACE_PATH,
   CHANNELS_THREAD_PATH,
@@ -171,13 +172,20 @@ export const getChannelsSpacePath = (spaceIdOrAlias: string): string => {
 };
 export const getChannelsRoomPath = (
   spaceIdOrAlias: string,
-  roomIdOrAlias: string
+  roomIdOrAlias: string,
+  eventId?: string
 ): string => {
-  const params = {
+  if (eventId) {
+    return generatePath(CHANNELS_ROOM_EVENT_PATH, {
+      spaceIdOrAlias: encodeURIComponent(spaceIdOrAlias),
+      roomIdOrAlias: encodeURIComponent(roomIdOrAlias),
+      eventId: encodeURIComponent(eventId),
+    });
+  }
+  return generatePath(CHANNELS_ROOM_PATH, {
     spaceIdOrAlias: encodeURIComponent(spaceIdOrAlias),
     roomIdOrAlias: encodeURIComponent(roomIdOrAlias),
-  };
-  return generatePath(CHANNELS_ROOM_PATH, params);
+  });
 };
 export const getChannelsThreadPath = (
   spaceIdOrAlias: string,

src/app/pages/paths.ts

@@ -91,6 +91,12 @@ export const BOTS_BOT_PATH = '/bots/:botId/';
 export const CHANNELS_PATH = '/channels/';
 export const CHANNELS_SPACE_PATH = '/channels/:spaceIdOrAlias/';
 export const CHANNELS_ROOM_PATH = '/channels/:spaceIdOrAlias/:roomIdOrAlias/';
+// Event-anchored channel room URL — discriminated `event/` segment so the
+// optional eventId does not collide with the sibling `thread/:rootId/`
+// sub-route. Search/inbox/mention/push permalinks land here so the timeline
+// can scroll to the cited event without dropping the user out of /channels/.
+export const CHANNELS_ROOM_EVENT_PATH =
+  '/channels/:spaceIdOrAlias/:roomIdOrAlias/event/:eventId/';
 export const CHANNELS_THREAD_PATH = '/channels/:spaceIdOrAlias/:roomIdOrAlias/thread/:rootId/';
 
 export const SPACE_SETTINGS_PATH = '/space-settings/';

src/app/utils/routeParent.ts

@@ -2,6 +2,7 @@ import { matchPath } from 'react-router-dom';
 import {
   BOTS_PATH,
   CHANNELS_PATH,
+  CHANNELS_ROOM_EVENT_PATH,
   CHANNELS_ROOM_PATH,
   CHANNELS_SPACE_PATH,
   CHANNELS_THREAD_PATH,
@@ -51,6 +52,19 @@ export const getRouteSectionParent = (pathname: string): string | null => {
         decodeURIComponent(threadMatch.params.roomIdOrAlias)
       );
     }
+    // Event-anchored permalink collapses to the same parent room view as
+    // thread does — so back from a search/notification permalink lands on
+    // the room timeline first, not on the space root.
+    const eventMatch = matchPath(
+      { path: CHANNELS_ROOM_EVENT_PATH, caseSensitive: true, end: false },
+      pathname
+    );
+    if (eventMatch?.params.spaceIdOrAlias && eventMatch?.params.roomIdOrAlias) {
+      return getChannelsRoomPath(
+        decodeURIComponent(eventMatch.params.spaceIdOrAlias),
+        decodeURIComponent(eventMatch.params.roomIdOrAlias)
+      );
+    }
     const roomMatch = matchPath(
       { path: CHANNELS_ROOM_PATH, caseSensitive: true, end: false },
       pathname