diff --git a/apps/client/src/features/comment/components/comment-content-view.test.tsx b/apps/client/src/features/comment/components/comment-content-view.test.tsx
index 96e01961..812deb43 100644
--- a/apps/client/src/features/comment/components/comment-content-view.test.tsx
+++ b/apps/client/src/features/comment/components/comment-content-view.test.tsx
@@ -15,6 +15,7 @@ vi.mock("@/features/comment/components/comment-editor", () => ({
 // case renders in isolation.
 vi.mock("@/features/page/queries/page-query.ts", () => ({
   usePageQuery: () => ({ data: undefined, isLoading: false, isError: false }),
+  usePageMetaQuery: () => ({ data: undefined, isLoading: false, isError: false }),
 }));
 vi.mock("@/features/share/queries/share-query.ts", () => ({
   useSharePageQuery: () => ({ data: undefined }),
diff --git a/apps/client/src/features/page/components/breadcrumbs/breadcrumb-path-equal.test.ts b/apps/client/src/features/page/components/breadcrumbs/breadcrumb-path-equal.test.ts
new file mode 100644
index 00000000..0002736d
--- /dev/null
+++ b/apps/client/src/features/page/components/breadcrumbs/breadcrumb-path-equal.test.ts
@@ -0,0 +1,53 @@
+import { describe, it, expect, vi } from "vitest";
+import { SpaceTreeNode } from "@/features/page/tree/types";
+
+// breadcrumb.tsx transitively imports @/main.tsx (via usePageMetaQuery ->
+// queryClient), whose module body calls ReactDOM.createRoot on a null root in
+// jsdom. Stub it so importing the pure helper under test doesn't run that
+// (breadcrumbPathEqual does not use queryClient, so a dummy is enough).
+vi.mock("@/main.tsx", () => ({ queryClient: {} }));
+
+import { breadcrumbPathEqual } from "./breadcrumb";
+
+// breadcrumbPathEqual is the ONLY point where a false-positive equality would
+// leave a stale/incorrect breadcrumb trail on screen: it decides whether the
+// selectAtom hands back the same reference (no re-render) for the ancestor chain.
+// Pin both directions — a too-loose equality goes stale on a rename; a too-tight
+// one loses the perf win.
+const node = (over: Partial<SpaceTreeNode>): SpaceTreeNode =>
+  ({ id: "a", slugId: "sa", name: "A", icon: "📄", ...over }) as SpaceTreeNode;
+
+describe("breadcrumbPathEqual", () => {
+  it("both null → true", () => {
+    expect(breadcrumbPathEqual(null, null)).toBe(true);
+  });
+
+  it("same reference → true", () => {
+    const p = [node({})];
+    expect(breadcrumbPathEqual(p, p)).toBe(true);
+  });
+
+  it("equal by id/slugId/name/icon (different arrays) → true", () => {
+    expect(breadcrumbPathEqual([node({})], [node({})])).toBe(true);
+  });
+
+  it("one side null → false", () => {
+    expect(breadcrumbPathEqual([node({})], null)).toBe(false);
+    expect(breadcrumbPathEqual(null, [node({})])).toBe(false);
+  });
+
+  it("different length → false", () => {
+    expect(
+      breadcrumbPathEqual([node({})], [node({}), node({ id: "b" })]),
+    ).toBe(false);
+  });
+
+  it.each(["name", "icon", "slugId", "id"] as const)(
+    "a changed %s → false (breadcrumb must re-render)",
+    (field) => {
+      expect(
+        breadcrumbPathEqual([node({})], [node({ [field]: "CHANGED" })]),
+      ).toBe(false);
+    },
+  );
+});
diff --git a/apps/client/src/features/page/components/breadcrumbs/breadcrumb.tsx b/apps/client/src/features/page/components/breadcrumbs/breadcrumb.tsx
index a74ce7aa..1f988947 100644
--- a/apps/client/src/features/page/components/breadcrumbs/breadcrumb.tsx
+++ b/apps/client/src/features/page/components/breadcrumbs/breadcrumb.tsx
@@ -41,7 +41,7 @@ function getTitle(name: string, icon: string) {
  * visually unchanged, so the breadcrumb no longer re-renders on every tree
  * event (it previously subscribed to the whole treeDataAtom).
  */
-function breadcrumbPathEqual(
+export function breadcrumbPathEqual(
   a: SpaceTreeNode[] | null,
   b: SpaceTreeNode[] | null,
 ): boolean {
diff --git a/apps/client/src/features/page/queries/invalidate-on-update-page.test.ts b/apps/client/src/features/page/queries/invalidate-on-update-page.test.ts
new file mode 100644
index 00000000..38b7f883
--- /dev/null
+++ b/apps/client/src/features/page/queries/invalidate-on-update-page.test.ts
@@ -0,0 +1,90 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import type { IPage } from "@/features/page/types/page.types";
+
+// A fresh QueryClient stands in for the app singleton (importing the real
+// @/main.tsx would run ReactDOM.createRoot, which has no DOM root in jsdom). The
+// factory constructs it (QueryClient can't be referenced in vi.hoisted — that
+// runs before imports resolve); we import the SAME mocked instance back to seed
+// and assert on it.
+vi.mock("@/main.tsx", async () => {
+  const { QueryClient } = await import("@tanstack/react-query");
+  return { queryClient: new QueryClient() };
+});
+
+import { queryClient as h_qc } from "@/main.tsx";
+import { invalidateOnUpdatePage } from "./page-query";
+
+const h = { qc: h_qc };
+
+// invalidateOnUpdatePage is the field-only (title/icon) tree path: instead of a
+// blanket invalidate it patches the affected node IN PLACE in every cached embed
+// subtree. The undefined-guard is LOAD-BEARING: a title-only socket event carries
+// icon:undefined, and without the guard `{...p, icon: undefined}` would WIPE the
+// icon in every cached subtree.
+const page = (over: Partial<IPage>): IPage =>
+  ({ id: "p1", title: "Old", icon: "📄", spaceId: "s1" }) as IPage &
+    typeof over as IPage;
+
+describe("invalidateOnUpdatePage — pointwise embed-cache patch", () => {
+  beforeEach(() => {
+    h.qc.clear();
+  });
+
+  it("title-only event updates title but PRESERVES the icon (undefined-guard)", () => {
+    const key = ["page-tree", "parent-1"];
+    h.qc.setQueryData<IPage[]>(key, [
+      { id: "p1", title: "Old", icon: "📄", spaceId: "s1" } as IPage,
+      { id: "p2", title: "Other", icon: "📁", spaceId: "s1" } as IPage,
+    ]);
+
+    // icon passed as undefined (a title-only update)
+    invalidateOnUpdatePage(
+      "s1",
+      "parent-1",
+      "p1",
+      "New Title",
+      undefined as unknown as string,
+    );
+
+    const patched = h.qc.getQueryData<IPage[]>(key)!;
+    const p1 = patched.find((p) => p.id === "p1")!;
+    const p2 = patched.find((p) => p.id === "p2")!;
+    expect(p1.title).toBe("New Title");
+    expect(p1.icon).toBe("📄"); // preserved, not wiped
+    // Sibling node untouched.
+    expect(p2.title).toBe("Other");
+    expect(p2.icon).toBe("📁");
+  });
+
+  it("icon-only event updates icon but preserves the title", () => {
+    const key = ["page-tree", "parent-1"];
+    h.qc.setQueryData<IPage[]>(key, [
+      { id: "p1", title: "Keep", icon: "📄", spaceId: "s1" } as IPage,
+    ]);
+
+    invalidateOnUpdatePage(
+      "s1",
+      "parent-1",
+      "p1",
+      undefined as unknown as string,
+      "🚀",
+    );
+
+    const p1 = h.qc.getQueryData<IPage[]>(key)!.find((p) => p.id === "p1")!;
+    expect(p1.icon).toBe("🚀");
+    expect(p1.title).toBe("Keep");
+  });
+
+  it("does not touch a subtree that lacks the updated node", () => {
+    const otherKey = ["page-tree", "unrelated"];
+    const before = [
+      { id: "x1", title: "X", icon: "❌", spaceId: "s1" } as IPage,
+    ];
+    h.qc.setQueryData<IPage[]>(otherKey, before);
+
+    invalidateOnUpdatePage("s1", "parent-1", "p1", "New", "🚀");
+
+    // Same reference back — the subtree without p1 is left as-is.
+    expect(h.qc.getQueryData<IPage[]>(otherKey)).toBe(before);
+  });
+});
diff --git a/apps/client/src/features/page/queries/page-query.ts b/apps/client/src/features/page/queries/page-query.ts
index 6abed784..525070b8 100644
--- a/apps/client/src/features/page/queries/page-query.ts
+++ b/apps/client/src/features/page/queries/page-query.ts
@@ -411,9 +411,11 @@ export function useRecentChangesQuery(spaceId?: string) {
     getNextPageParam: (lastPage) =>
       lastPage.meta.hasNextPage ? lastPage.meta.nextCursor : undefined,
     // KEEP refetchOnMount:true (against the global default false): recent-changes
-    // is invalidated only while a mounted observer exists, and the widget isn't
-    // always mounted — an event that lands while it's unmounted marks it stale but
-    // the global refetchOnMount:false would not re-fetch on remount → stale list.
+    // IS invalidated on page create/update/move/delete, but invalidateQueries only
+    // marks an UNMOUNTED query stale — it doesn't refetch it. The widget isn't
+    // always mounted, so an event that lands while it's unmounted leaves it stale,
+    // and the global refetchOnMount:false would not re-fetch on remount. The mount
+    // refetch closes that gap.
     refetchOnMount: true,
   });
 }
@@ -447,10 +449,12 @@ export function useDeletedPagesQuery(
     enabled: !!spaceId,
     placeholderData: keepPreviousData,
     staleTime: 0,
-    // KEEP refetchOnMount:true: the "trash-list" key is never invalidated (no
-    // socket/mutation path), so opening the trash after deleting/restoring a page
-    // must refetch on mount — the global refetchOnMount:false would show a stale
-    // trash missing the just-deleted page until a hard reload.
+    // KEEP refetchOnMount:true: ["trash-list"] IS invalidated by the
+    // move-to-trash / delete / restore mutations, but invalidateQueries only marks
+    // an unmounted query stale — it doesn't refetch it. The trash panel isn't
+    // usually mounted when a page is trashed, so on opening it the global
+    // refetchOnMount:false would show a stale list; the mount refetch closes that.
+    // (Do NOT remove the three trash-list invalidations — they are not dead code.)
     refetchOnMount: true,
   });
 }
diff --git a/apps/client/src/features/share/components/share-modal.test.tsx b/apps/client/src/features/share/components/share-modal.test.tsx
index c3d96afd..d9c9d01f 100644
--- a/apps/client/src/features/share/components/share-modal.test.tsx
+++ b/apps/client/src/features/share/components/share-modal.test.tsx
@@ -28,6 +28,7 @@ vi.mock("@/features/share/queries/share-query.ts", () => ({
 
 vi.mock("@/features/page/queries/page-query.ts", () => ({
   usePageQuery: () => ({ data: { id: "page-1", title: "Doc" } }),
+  usePageMetaQuery: () => ({ data: { id: "page-1", title: "Doc" } }),
 }));
 
 vi.mock("@/features/space/queries/space-query.ts", () => ({
diff --git a/apps/client/src/features/space/queries/space-query.ts b/apps/client/src/features/space/queries/space-query.ts
index 96425808..b98f258c 100644
--- a/apps/client/src/features/space/queries/space-query.ts
+++ b/apps/client/src/features/space/queries/space-query.ts
@@ -38,6 +38,12 @@ export function useGetSpacesQuery(
     queryKey: ["spaces", params],
     queryFn: () => getSpaces(params),
     placeholderData: keepPreviousData,
+    // KEEP refetchOnMount:true (against the global default false): the ["spaces"]
+    // key is invalidated only by same-tab mutations (no socket path), so a
+    // cross-actor change — an admin adding/removing THIS user from a space — has
+    // no local mutation or socket event and would leave the space list stale until
+    // a hard reload. The mount refetch is its only cross-actor freshness path.
+    refetchOnMount: true,
   });
 }