Remove Plausible analytics from the mobile app

[micahflee]

Fixes #120. Part of lockdown-systems/collective-tracking#51 — remove app telemetry entirely rather than re-implement it. Usage insight continues to come from cyd-server's own authenticated data.

Ripped out fully: no no-op transport, no PlausibleEvents vocabulary left behind.

Summary

-├── services/analytics.ts    # trackEvent(): POST https://plausible.io/api/event
-├── types/analytics.ts       # PlausibleEvents catalog + PlausibleEventName
 app/_layout.tsx
-  useEffect(() => trackEvent(PlausibleEvents.APP_OPENED), [])
 services/bluesky-sign-in.ts
-  trackEvent(PlausibleEvents.BLUESKY_USER_SIGNED_IN)
 controllers/bluesky/job-runner.ts
-  const JOB_TYPE_TO_EVENT: Partial<Record<BlueskyJobType, PlausibleEventName>>
-  // Delete job events can be added later when analytics are set up for them
 services/__tests__/bluesky-sign-in.test.ts
-  jest.mock("@/services/analytics", () => ({ trackEvent: jest.fn() }))

The TODO about delete-job events dies with the map — that's the point of the epic's decision.

Evidence

• Before: grep -ri plausible hits services/analytics.ts, types/analytics.ts, and their three consumers; every job-runner dispatch starts with a trackEvent call.
  After: tsc --noEmit passes, expo lint passes, npx jest — 79 suites / 902 tests passed (6 pre-existing skips) — and grep -ri plausible over app code returns zero hits.

What stays (not Plausible)

• /user/activity (on mount), /bluesky-progress (including the unauthenticated fallback), push notifications, IAP — all stay.
• No App Store/Play privacy-label changes are planned (nothing is declared today; see the epic).

Merge Danger

Door: two-way — pure deletion; git revert restores everything.

Blast Radius: app startup, Bluesky sign-in, and the Bluesky job runner dispatch (one telemetry call each, nothing replaces them). No UI, settings, or store-listing changes. Ships with the next release whenever that is; released versions swallow the failed POST silently, so nothing breaks before then.

(This was written by an LLM.)