Claude in Chrome extension 1.0.85: all Claude Code tab operations return 'No tab available' on Chrome 149 AND 151 (side panel automation works)

Summary

Claude in Chrome browser automation worked all morning, then Chrome auto-updated from 149.0.7827.201 to 151.0.7922.110 (the Aug 11 stable release) and restarted. Since that moment, every tab operation returns No tab available while browser registration works fine.

Environment

• macOS 26.5.1 (Apple Silicon)
• Chrome 151.0.7922.110 (stable), updated from 149.0.7827.201 mid-session
• Claude Code CLI 2.1.231
• Claude extension: reinstalled fresh from Chrome Web Store today (id fcoeoabgfenejglbffodgkkbkcdhcgfn)

Behavior

Works:

• list_connected_browsers returns the browser, connectedAt refreshes when the extension icon is clicked
• select_browser succeeds ("Connected to browser")
• The extension side panel (claude.ai chat) is fully functional

Fails, always with No tab available:

• tabs_context_mcp (with createIfEmpty: true)
• tabs_create_mcp

A normal website is loaded and focused in the user's regular profile window.

Remediation attempted (all failed)

1. /mcp reconnect (multiple times), plus select_browser re-selection after each reconnect
2. Extension toggle off/on in chrome://extensions
3. Extension remove + reinstall (registered with a new deviceId, same error)
4. Side panel closed during automation
5. Site access verified "On all sites"
6. Native messaging host killed and respawned; discovered the wrapper script (~/.claude/chrome/chrome-native-host) pointed at CLI version 2.1.214 while the CLI was 2.1.231; after a Claude Code restart the wrapper regenerated to 2.1.231 and the host process runs 2.1.231 (verified via ps) — still the same error
7. Fully ordered cold start: quit Chrome and Claude Code, start Chrome first (extension boots, host spawns), then claude --continue so the MCP server starts last — still the same error

Notes

• Timing strongly suggests the Chrome 149 -> 151 jump (or the extension auto-update that came with the restart) as the trigger. Chrome 151.0.7922.137's release notes include use-after-free security fixes in TabStrip and Extensions.
• Same error string as older issues #37538, #21106, #51160, but those predate Chrome 151 and their workarounds (reinstall, reconnect, restarts) do not help here.