* feat(apps): add AppRenderer element with imperative ref (#1262)
Introduces a thin host-side shell for embedded MCP Apps. The renderer
owns the iframe element and the AppBridge lifecycle; the wiring layer
constructs the bridge from the active MCP Client via bridgeFactory and
drives input/result/cancellation through the imperative ref handle.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* review: address PR feedback on AppRenderer
- Document BridgeFactory stability requirement (unstable identity thrashes
the iframe on every render).
- Null bridgeRef synchronously inside teardown() before awaiting disposal,
so a concurrent unmount cleanup cannot dispose the same bridge twice.
- Comment the iframe trust model: the outer frame loads the inspector's
trusted same-origin sandbox-proxy, which sandboxes the actual app
content. Adding `sandbox` to this frame would block the postMessage
bridge.
- Rename `Error` story export to `BridgeError` to avoid shadowing the
global Error constructor; drop the `globalThis.Error` workaround.
- Comment flushAsync to explain the two-tick microtask budget.
- Add unmount-while-tearing-down test to lock in the no-double-dispose
guarantee.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
323f42d11c