#11705 froze config/quality/api-typecheck-baseline.json days before it merged;
by then six diagnostics had regressed on release/v3.8.51, so the gate turned
every open PR red on arrival (api-route-typecheck run 33299099596):
- webhooks/[id]/test/route.ts: duplicate `import { getWebhook, recordWebhookDelivery }`
left by the barrel migration (#12051) — a real defect, ESM rejects duplicate
bindings at load time.
- providers/volcengine-plan/connect/**: `if (!x.ok)` / `if (!validation.success)`
do not narrow discriminated unions without strictNullChecks (repo is
strict:false) — compare `=== false` so `.error` type-checks.
- providers/route.ts: type the ["id","provider"] column projection instead of
passing `unknown` into cleanupProviderModelsAfterConnectionDelete.
- tunnels/tailscale/install/route.ts: spread PublicSafeTunnelErrorBody into the
Record<string, unknown> payload pushEvent expects.
Gate back to OK (289 errors, all frozen) and the 12 diagnostics that had
disappeared since the freeze are ratcheted out of the baseline (--update).
Boarded in a combined worktree: typecheck:core, check:dashboard-typecheck, check:file-size, check:changelog-integrity, check:complexity, check:cognitive-complexity, check:cycles, check-deps all green. Clean, self-contained addition (5 new files, 0 modifications to existing code) that mirrors the existing dashboard-typecheck baseline-ratchet pattern. Thanks for closing a real coverage gap — API routes had no dedicated typecheck gate.
