[BUG] Bundled GrowthBook clientKey still returns 400 "Invalid API Key" on 2.1.266 — Remote Control fails closed (regression/reopen of #64151)

Summary

Same bug as #64151 (closed by stale-bot without a fix), still present on 2.1.266 — much later than the versions originally reported (2.1.149 / 2.1.157 / 2.1.158). The bundled GrowthBook clientKey sdk-zAZezfDKGoZuXXKe (apiHost https://cdn.growthbook.io) is currently rejected by the CDN, so zero feature flags load and Remote Control fails closed with a misleading network-sounding error.

Environment

• Claude Code 2.1.266, macOS arm64
• claude auth status: loggedIn: true, authMethod: claude.ai, apiProvider: firstParty, analyticsDisabled: false, subscriptionType: max
• No telemetry/GrowthBook env vars set (DISABLE_TELEMETRY, DISABLE_GROWTHBOOK, CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC, DO_NOT_TRACK all unset — verified via env)

Repro (machine-independent, no auth required)

$ curl https://cdn.growthbook.io/api/features/sdk-zAZezfDKGoZuXXKe
{"status":400,"error":"Invalid API Key"}

Reproduced 5/5 consecutive attempts just now (2026-09-09). Confirmed sdk-zAZezfDKGoZuXXKe is still the hardcoded clientKey in the 2.1.266 binary via strings.

claude doctor output

Remote Control
Couldn't verify Remote Control eligibility — the feature-flag service was unreachable (offline or blocked). Retry, or run with --debug / claude doctor for details.
- Remote Control availability could not be verified (no server response this session)

Failed consistently across 3 separate claude doctor runs, several minutes apart.

Ruled out before filing

• Corporate proxy/VPN: confirmed both api.anthropic.com and cdn.growthbook.io return normal, unblocked responses through the network in question (valid TLS, correct HTTP status, expected JSON bodies) — this is a genuine upstream key rejection, not a network block.
• Env vars that are known to disable GrowthBook evaluation: confirmed absent.
• Stale/cached auth: claude auth status shows a valid, current claude.ai Max session.

Impact

Remote Control (and presumably Channels, per #64151) silently unavailable. The error message ("feature-flag service was unreachable (offline or blocked)") reads as a local network problem, which sends users on a long, unproductive troubleshooting path (proxy/VPN checks, cert issues) before finding this is a server-side key problem — as happened here.

Ask

1. Rotate/restore the GrowthBook clientKey so cdn.growthbook.io accepts it, and confirm the fix in this issue rather than letting it go stale again.
2. Since #64151 was auto-closed by inactivity without a fix or maintainer response, consider exempting confirmed-repro issues with a live has repro label from the stale-bot, or at minimum leave a closing comment when a real fix ships.

Related: #64151 (same key, same symptom, closed by staleness bot 2026-09-05 without resolution).