Add a per-profile subscription: true opt-in that lets a claude-code worker run on
the operator's Claude subscription when there is no off-subscription endpoint for it
(e.g. sonnet on ccs). When set, the launcher injects neither ANTHROPIC_BASE_URL nor
ANTHROPIC_AUTH_TOKEN and skips SubscriptionGuard's base_url requirement for that
profile only, logging a WARN naming the profile. subscription: true alongside a
baseUrl is refused as contradictory. The default (absent/false) keeps today's hard
refusal unchanged; every other profile stays allowlist-checked and SubscriptionGuard
is untouched.