Bug fixes:
1. OAuth token refresh (#3149): buildHttpRequestInit() now attempts silent refresh
via refresh_token before triggering full browser re-auth. Added refresh() method
to McpOAuthProvider. Includes test isolation fix for discovery mock.
2. Quota error STOP (#3126): Added STOP_MESSAGE_PATTERNS in model-error-classifier
that take precedence over RETRYABLE_MESSAGE_PATTERNS. Message-only quota errors
now non-retryable. Runtime-fallback: quota_exceeded with 'retrying in' signal
still triggers fallback (provider-managed auto-retry). Restored removed patterns.
3. Compaction loop (#3127): MAX_RECOVERY_ATTEMPTS=3 cap + additional suppression
guard from opencode session in degradation monitor.
Also: refactored extractAutoRetrySignal to auto-retry-signal.ts, new regression
tests for quota classifier and compaction degradation monitor.
YeonGyu-Kim