Remote Control fails: `bridge_state: failed - /login` (bridge reachable, valid personal-account token rejected)

Summary: /remote-control fails immediately with bridge_state: failed - /login. The Remote Control bridge host is fully reachable and the account is eligible, but the auth handshake is rejected. Appears to be a server-side account-provisioning / rollout gap rather than a client issue.

Environment

• App: Claude desktop 1.11187.4 (Windows, runFullTrust MSIX build - not AppContainer-sandboxed)
• Engine: claude-code 2.1.165
• Plan: Max, web-billed, personal account (not part of an organization)
• Account feature flag: ccRemoteControlDefaultEnabled: true

Symptom (logs)

[info]  Enabling remote control for session local_.
[info]  [remote-control] bridge_state: failed - /login
[error] Failed to toggle remote control for local_.: /login

Also intermittently in the renderer: ["account_profile"] data is undefined and TypeError: Failed to fetch.

What was verified clean (extensive client-side diagnosis)

• Bridge host reachable: wss://bridge.claudeusercontent.com ? HTTP 426 Upgrade Required with a valid Google Trust Services cert; resolves to 160.79.104.10 via both OS DNS and DoH (Cloudflare + Google).
• Network: no proxy, no VPN/WARP, no TLS interception; claude.ai / api.anthropic.com reachable with genuine certs.
• Auth env: no ANTHROPIC_API_KEY / CLAUDE_CODE_OAUTH_TOKEN shadowing; default base URL.
• Token: desktop oauth:tokenCache is recently minted and valid (chat works with it). Full sign-out/sign-in performed twice.
• Storage: IndexedDB / Local State / cookies reset and rebuilt healthy.
• Settings: no disableRemoteControl; not org-gated (personal account, so the admin toggle doesn't apply).
• Other: disk space fine, Controlled Folder Access off, only Windows Defender (no 3rd-party AV), no OneDrive redirection, file perms writable.

Diagnosis

The bridge is reachable and the account is eligible, yet the /api/auth/trusted_devices handshake redirects to /login - i.e. the relay rejects a valid personal-account OAuth token / device-trust for the Remote Control bridge specifically, while the same token works for normal chat. claude.ai also shows no trusted-devices UI for this account.

This looks like the same class of failure as #60606 and #64070.

Repro

1. Open the desktop app, start a local session.
2. Toggle Remote Control (/remote-control).
3. Fails instantly with /login; no device pairing dialog appears.