Coverage 83.6 to 87.36% lines, 81.63 to 84.14% branches. Mutation testing across five packages: image-engine 85, media-engine 92, doc-engine 87, shared+enterprise 86, apps/api security and jobs slice. Runs all five lanes weekly. Fixes the silently-broken mutation CI (babel pin), a redact-pdf envelope-shape test bug, an untested enterprise license valid-signature path, and an audit test that only exercised a hand-copied reproduction. Test and config only, no product code changes beyond the babel pin and one test-only oidc export. Full suite: 16,712 pass, 0 fail.
Five fixes to the PostHog event stream, from an audit of what we actually collect versus what's flowing in. Each one is test-first.
## What changed
**Silenced the `$opt_in` noise.** `initAnalytics` called `opt_in_capturing()` on every page load to clear a stale opt-out flag, and posthog-js emits an `$opt_in` event on every call. That was 10k+ events a month (up to 55 per user) carrying no signal: analytics is on by default with an admin opt-out, so there is no per-user consent to record. Both call sites now pass `captureEventName: false`.
**Split the onboarding survey out of `feedback_submitted`.** The onboarding usage survey rode the same event as real feedback, so about 93% of "feedback" was actually onboarding profiling. It now emits `onboarding_survey_submitted`, so feedback metrics mean feedback again.
**Set `pipeline_executed.file_count`.** It was declared in the properties interface but never populated. A pure `pipelineExecutedProps` helper now derives it (batch size for a batch run, else 1) and is shared by the success and failure paths, which also drops a duplicated payload.
**Tracked OIDC login failures.** All six OIDC callback failure branches bumped the Prometheus counter and wrote an audit log but never emitted `auth_login_failed`. A `recordOidcFailure` helper mirrors the password path.
**Added `TELEMETRY.md`.** A contributor-facing event dictionary: every event, its properties, where it fires, and the privacy invariants, with the allowlists as source of truth. A drift test fails if any `ANALYTICS_EVENTS` value goes undocumented.
I left the published telemetry guide (`apps/docs/guide/telemetry.md`) alone. It is high-level and still accurate, and editing it would pull in the 21-locale stale-gate for no gain.
## Verification
- Unit (63 tests): `analytics-events`, `telemetry-doc-drift`, `api/analytics`, `web/analytics`, `worker.behavior`
- Integration (41 tests): `oidc-auth`, `feedback`
- Full typecheck across all 9 workspaces
- Biome clean on the changed files
All green locally.
