error-reporting.ts silencing rules: which error types are silenced and why

Current classifySilenced() branches (post-PRs #1148–#1153): - OutputError → 'output_error' (piped output closed early) - ContextError → 'context_missing' (user omitted required value; never a CLI bug) - AuthError (any reason: not_authenticated, expired, invalid) → 'auth_expected' (all auth reasons are user/env state after CLI-19 fix) - ApiError status >400 && <500 → 'api_user_error' - ApiError + isSearchQueryParseError() → 'api_query_error' (status 400 with 'Error parsing search query' detail) - TypeError + isNetworkError() → 'network_error' (raw 'fetch failed' only) - else → null (captured) Metric emission must never block error handling — all metric/logger calls in recordSilencedError() are wrapped in try/catch.