[BUG] Invalid server route when opening or creating a session in OpenCode Web

[Gogonemnem]

Description

When using OpenCode Web remotely in Chromium, the web UI can fail after a project has been selected. Opening an existing session or clicking New session may leave the UI unresponsive. Chromium showed:

Error: Invalid server route
    at ra (.../assets/index-<hash>.js:...)
    at get serverKey (.../assets/index-<hash>.js:...)

The OpenCode backend remains healthy and can access the selected project.

The separate directory-picker problem is already reported in #39434. This report is only about the session/browser-route error after a project is selected.

Plugins

None

OpenCode version

Current beta: 0.0.0-beta-202608031317.

Also observed with stable 1.18.11.

Steps to reproduce

1. Run opencode web in Docker with password protection enabled.
2. Mount a project directory into the container and select that project in OpenCode Web.
3. Open the web UI from another device on the private network.
4. Try to open an existing session or click New session.
5. Observe that the UI may become unresponsive and Chromium can show Invalid server route.

Screenshot and/or share link

No response

Operating System

Ubuntu Docker host; Chromium client on Windows.

Terminal

No response

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• "Open project" dialog always shows "No folders found" — GET /file missing required path param #39434: Same root cause — GET /find/file returns no results while GET /file?path=&directory=... works correctly; the directory picker shows "No folders found" and the New Session button becomes unresponsive. The issue there traces this to the frontend calling the file-listing SDK without the required path parameter.
• Web UI: "New Session" button stays disabled even though server is correctly bound to project directory #39330: "New Session" button stays disabled in web UI even though the server is correctly bound to the project directory — same user-visible symptom in a remote/networked setup.