fix(dream): drop ANTHROPIC_API_KEY gate from patterns phase

[brettdavies]

Closes #2278

Summary

The bug. gbrain dream --phase patterns returns { status: 'skipped', reason: 'no_api_key' } on any non-Anthropic stack (litellm-proxy, codex-proxy, ollama, openrouter, any openai-compat deployment) regardless of how models.dream.patterns resolves. The phase never reaches its subagent submission below, which would have routed through the gateway and dispatched correctly.

The fix. Drop the if (!process.env.ANTHROPIC_API_KEY) short-circuit in src/core/cycle/patterns.ts. The subagent submission below already uses the same gateway model-tier resolver that synthesize uses; when the gateway is misconfigured, dispatch surfaces a clear AIConfigError per-call rather than a misclassified skipped: no_api_key verdict.

Diagnosis

• src/core/cycle/patterns.ts:67-69 (pre-patch) short-circuits when ANTHROPIC_API_KEY is unset:

  ts if (!process.env.ANTHROPIC_API_KEY) { return skipped('no_api_key', 'ANTHROPIC_API_KEY unset; pattern detection skipped'); }

• The submission immediately below the gate calls submitSubagent(...), which routes through gateway.toolLoop() via the recipe registered for whichever model the resolver selected. That path already supports every non-Anthropic recipe (litellm, ollama, openrouter, openai, claude-cli, …).

• The sibling synthesize phase removed its equivalent gate (see the makeJudgeClient docstring at src/core/cycle/synthesize.ts:804, which "preserves the legacy 'no ANTHROPIC_API_KEY' cheap-skip semantics" while delegating real auth probing to the gateway recipe's auth_env.required machinery).

The patterns phase carries the same pattern in its body but never had the gate updated when the rest of the cycle moved to gateway-routed dispatch.

Reproduction

1. Fresh brain with no ANTHROPIC_API_KEY in env, paid traffic routed through any non-Anthropic recipe.
2. gbrain config set models.dream.patterns litellm:gpt-5.4 (or any non-anthropic:* model).
3. gbrain dream --phase patterns --json.
4. Expected: subagent dispatches and returns pattern detections.
5. Actual (pre-patch): { status: 'skipped', reason: 'no_api_key' }.

Tests

• Manual verification on a brain with models.dream.patterns = litellm:gpt-5.4 and no ANTHROPIC_API_KEY in env: pre-patch returned the skipped verdict; post-patch dispatched through the litellm route and returned pattern detections.
• No new unit test added; the change deletes a literal env-var check and the existing patterns-phase tests cover the dispatch path. Happy to add a regression test that asserts the phase reaches the gateway when ANTHROPIC_API_KEY is unset if the maintainer prefers.

Adjacent observation (follow-up, not in this PR)

Other phases / commands may carry similar stale ANTHROPIC_API_KEY checks that pre-date the gateway-routed dispatch. Worth a rg -n 'ANTHROPIC_API_KEY' src/core/cycle src/commands sweep to catch siblings. The synthesize phase is already clean; patterns is the one this PR fixes. Anything else found would be a separate small PR per site.