diff --git a/docs/gamecult/ratatoskr-target.md b/docs/gamecult/ratatoskr-target.md
index b56c90f8..519db4b1 100644
--- a/docs/gamecult/ratatoskr-target.md
+++ b/docs/gamecult/ratatoskr-target.md
@@ -97,9 +97,11 @@ Probes run by Imagination on 2026-10-31, session `self-2026-10-29-eureka`.
    events from the Minds' stewardship documents; each project room's alias is
    `#<repo lowercased>` (runbook 146-150). This is the only place the client
    can learn a not-yet-joined room's steward today: hierarchy `canonical_alias`
-   joined to the root `org.gamecult.stewardships`. Follow-up
-   `ratatoskr:follow_up:stewardships-carry-room-ids` asks the projection to
-   name room ids so the client stops leaning on the alias convention.
+   joined to the root `org.gamecult.stewardships`. The
+   projection now also names room ids under `@rooms.projects` and
+   `@rooms.file_zones` (gamecult-ops #111); the client reads `file_zones` for
+   the Media row (`mediaRoom.ts`) and still joins projects by alias, since
+   nothing yet consumes `@rooms.projects`.
 5. **Sync and storage** (`src/client/initMatrix.ts`). The client uses
    matrix-js-sdk 41.7.0 with `IndexedDBStore` (`web-sync-store`, 15-19) and the
    Rust crypto store, and `startClient({ lazyLoadMembers: true })` (43-47): v2
diff --git a/src/app/features/estate/mediaRoom.test.ts b/src/app/features/estate/mediaRoom.test.ts
index af53c12b..934caaae 100644
--- a/src/app/features/estate/mediaRoom.test.ts
+++ b/src/app/features/estate/mediaRoom.test.ts
@@ -45,7 +45,7 @@ describe('the Media row of a Mind', () => {
       throw new Error('must not be asked');
     });
     const carried = mediaRoomIdFromStewardships(
-      { void: ['GameCult/x'], media: { void: '!c:gamecult.org' } },
+      { void: ['GameCult/x'], '@rooms': { file_zones: { void: '!c:gamecult.org' } } },
       'void'
     );
     expect(carried).toBe('!c:gamecult.org');
@@ -58,7 +58,23 @@ describe('the Media row of a Mind', () => {
 
   it('ignores a stewardships state that carries no id for the Mind, or something that is not a room id', () => {
     expect(mediaRoomIdFromStewardships({ void: ['GameCult/x'] }, 'void')).toBeUndefined();
-    expect(mediaRoomIdFromStewardships({ media: { void: 'nope' } }, 'void')).toBeUndefined();
+    expect(
+      mediaRoomIdFromStewardships({ '@rooms': { file_zones: { void: 'nope' } } }, 'void')
+    ).toBeUndefined();
+    // the project ids beside it, another Mind's id, and the old provisional key carry nothing for this Mind
+    expect(
+      mediaRoomIdFromStewardships(
+        {
+          '@rooms': { projects: { x: '!p:s' }, file_zones: { kiko: '!k:s' } },
+          media: { void: '!m:s' },
+        },
+        'void'
+      )
+    ).toBeUndefined();
+    // a Mind named "constructor" must not read an inherited property as an id
+    expect(
+      mediaRoomIdFromStewardships({ '@rooms': { file_zones: {} } }, 'constructor')
+    ).toBeUndefined();
     expect(mediaRoomIdFromStewardships(undefined, 'void')).toBeUndefined();
   });
 
diff --git a/src/app/features/estate/mediaRoom.ts b/src/app/features/estate/mediaRoom.ts
index a5f09664..5d1503b6 100644
--- a/src/app/features/estate/mediaRoom.ts
+++ b/src/app/features/estate/mediaRoom.ts
@@ -2,20 +2,29 @@
  * A Mind's media room: the file-zone room Eureka provisions under the alias #<mind>-files:<server>.
  * The navigator shows a Media row for every Mind; this module decides what that row says and where it points.
  * A room id carried by the root Space's org.gamecult.stewardships state wins over the alias; the alias is the
- * convention until the provisioning projection carries ids (ratatoskr:follow_up:stewardships-carry-room-ids).
+ * fallback for a Mind whose zone the provisioning run has not recorded yet.
  */
 import { EstateRoom } from './buildEstate';
 
 export const STEWARDSHIPS_KEY = 'org.gamecult.stewardships';
 
+/** Where provisioning records room ids in the stewardships state (gamecult-ops synapse-accounts-hand-managed.py ROOMS_KEY). "@" is no legal Matrix localpart, so no Mind can own the key. */
+export const ROOMS_KEY = '@rooms';
+
 export const mediaAlias = (mind: string, server: string): string => `#${mind}-files:${server}`;
 
 /**
- * The room id the stewardships state names for a Mind's media room, if it does. The state's mind-to-repos
- * lists are not read here; the id lives under `media[<mind>]` (provisional shape, awaiting the follow-up above).
+ * The room id the stewardships state names for a Mind's media room, under `@rooms.file_zones[<mind>]`.
+ * The state's mind-to-repos lists are not read here.
  */
 export const mediaRoomIdFromStewardships = (content: unknown, mind: string): string | undefined => {
-  const id = (content as { media?: Record<string, unknown> } | null | undefined)?.media?.[mind];
+  const rooms = (
+    content as
+      | Record<string, { file_zones?: Record<string, unknown> } | undefined>
+      | null
+      | undefined
+  )?.[ROOMS_KEY];
+  const id = rooms?.file_zones?.[mind];
   return typeof id === 'string' && id.startsWith('!') ? id : undefined;
 };