feat(shell): push project switches to embedded apps over the live bridge

src/components/shell/IframeHost.tsx

@@ -111,14 +111,25 @@ export function IframeHost({
       bridge.dispose();
       bridgeRef.current = null;
     };
-  }, [app, app.url, app.trust, webId, workspacePod, scope, allowWrite, project, podFetch, onResize, onOpen]);
+    // `project` is intentionally NOT a dep: a project switch must NOT tear down
+    // and recreate the bridge (its proactive welcome would go out at the
+    // un-negotiated host version and a v1 app drops it). It's pushed to the live
+    // bridge via setProject below, exactly like theme.
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [app, app.url, app.trust, webId, workspacePod, scope, allowWrite, podFetch, onResize, onOpen]);
 
   // Push shell theme changes to the live bridge so the embedded app's chrome
   // tracks the shell without re-mounting the iframe.
   useEffect(() => {
     bridgeRef.current?.setTheme(theme);
   }, [theme]);
 
+  // Push project switches to the live bridge so an embedded project-scoped app
+  // (Projects) follows the shell's switcher — again without re-mounting the frame.
+  useEffect(() => {
+    bridgeRef.current?.setProject(project ? { id: project.id, name: project.name } : null);
+  }, [project]);
+
   if (!app.url) {
     return (
       <div className="grid h-full place-items-center p-8 text-sm text-muted-foreground">

src/lib/shell/bridge.ts

@@ -83,6 +83,12 @@ export interface BridgeOptions {
 export interface Bridge {
   /** Push a new color mode to the app (re-broadcasts welcome). Idempotent. */
   setTheme(theme: BridgeTheme): void;
+  /** Push a project switch to the app (re-broadcasts welcome). Idempotent.
+   *  Mirrors {@link setTheme}: the frame stays mounted and the negotiated
+   *  protocol version is preserved, so the welcome actually reaches the app —
+   *  unlike tearing down and recreating the bridge, whose proactive welcome
+   *  goes out at the un-negotiated host version and a v1 app drops it. */
+  setProject(project: BridgeIdentity["project"]): void;
   dispose(): void;
 }
 
@@ -392,6 +398,11 @@ export function createBridge(opts: BridgeOptions): Bridge {
       currentTheme = theme;
       welcome();
     },
+    setProject(project: BridgeIdentity["project"]) {
+      if ((currentIdentity.project?.id ?? null) === (project?.id ?? null)) return;
+      currentIdentity = { ...currentIdentity, project };
+      welcome();
+    },
     dispose() {
       window.removeEventListener("message", onMessage);
       unsubscribe();

src/lib/shell/context.tsx

@@ -95,6 +95,8 @@ const NOTES_URL = siblingUrl(process.env.NEXT_PUBLIC_APP_NOTES_URL, 3120, "/note
 const CONTACTS_URL = siblingUrl(process.env.NEXT_PUBLIC_APP_CONTACTS_URL, 3130, "/contacts");
 const CALENDAR_URL = siblingUrl(process.env.NEXT_PUBLIC_APP_CALENDAR_URL, 3140, "/calendar");
 const PHOTOS_URL = siblingUrl(process.env.NEXT_PUBLIC_APP_PHOTOS_URL, 3150, "/photos");
+// Projects serves its app surface at the origin root (no sub-route).
+const PROJECTS_URL = siblingUrl(process.env.NEXT_PUBLIC_APP_PROJECTS_URL, 3160, "");
 // Slides (mind-slides-v0) is embedded at its `/studio` route. It brokers like the
 // rest of the suite (its `src/lib/solid/broker.ts` does the v1 handshake), so
 // embedded it uses the shell's SSO + pod — decks save to `{shellPod}mind-slides/
@@ -245,6 +247,15 @@ function builtinApps(): HostedApp[] {
       trust: "first-party",
       widgets: [RECENT_WIDGET],
     },
+    {
+      key: "projects",
+      label: "Projects",
+      icon: "📋",
+      enabled: true,
+      url: PROJECTS_URL,
+      embed: "iframe",
+      trust: "first-party",
+    },
     {
       key: "notes",
       label: "Notes",