Chrome extension bridge rejects valid OAuth token: Invalid token or user mismatch

Bug

Claude Code CLI (v2.1.86) with --chrome cannot connect to Chrome extension (v1.0.64). The bridge at wss://bridge.claudeusercontent.com rejects the extension's OAuth token with {"type":"error","error":"Invalid token or user mismatch"} (close code 1008).

The token IS valid

The rejected token returns 200 OK from GET /api/oauth/profile with matching account UUID, email, and org between CLI and extension. Token is not expired. Extension uses OAuth client dae2cad8-15c5-43d2-9046-fcaecc135fa4 (Claude for Chrome).

Steps to reproduce

1. claude --chrome (CLI v2.1.86, macOS ARM64)
2. Chrome extension v1.0.64 installed, same account
3. In extension service worker console, connect to bridge WebSocket
4. Send connect message with valid oauth_token
5. Bridge responds: Invalid token or user mismatch, closes 1008

What was ruled out

• Account mismatch (UUIDs identical: both f92efbce-...)
• Token expiration (not expired)
• Network issues (WebSocket connects, auth rejected)
• Extension not working (side panel chat works fine)

Environment

macOS Darwin 25.3.0, Claude Code 2.1.86, Chrome Extension 1.0.64, Claude Max subscription