Web deep-linked session pages can crash on initial render #21569

Description

Deep-linked web session pages can crash before session messages finish loading. The app lands on the error screen with TypeError: Cannot read properties of undefined (reading 'filter') from the built session bundle.

Root cause: packages/app/src/pages/session.tsx creates the messages memo before messagesReady, but still calls messagesReady() inside the memo body. On first render that can leave the downstream userMessages = messages().filter(...) path evaluating from an invalid state.

Plugins

No response

OpenCode version

0.0.0--202604082020 (reproduced on built local binary)

Steps to reproduce

1. Build the local binary and run opencode serve.
2. Open a deep-linked session route in the web UI (/<directory>/session/<id>).
3. Observe the app error boundary instead of the session page.
4. Error details show TypeError: Cannot read properties of undefined (reading 'filter').

Screenshot and/or share link

No response

Operating System

Ubuntu 24.04

Terminal

Ghostty