fix(insights): honest assistant pipeline — gates, tombstones, retries, truthful states

The two-o'clock status crons generated for every account, ignoring both
the per-user coach opt-out and the operator kill switch; they now share
one gated discovery that also skips users the pregenerate pass will
rewarm anyway, and the mood card finally gets the nightly run the other
six always had. Deleted measurements no longer feed any prompt. Locales
without an assistant language fall back to English consistently instead
of German texts with English fallbacks. A rate-limited regenerate stops
claiming success, the dashboard briefing state distinguishes a missing
provider from a pending generation and serves a stale briefing with its
timestamp instead of hiding it, narrative warming actually processes
oldest first, and worker failures reach the error tracker through one
shared reporter while the insight queues gain real retries.

src/components/settings/__tests__/disable-coach-card.test.tsx

@@ -56,6 +56,7 @@ function buildUser(disableCoach: boolean): AuthUser {
     avatarUrl: null,
     glucoseUnit: null,
     unitPreference: "metric",
+    timeFormat: "AUTO",
     disableCoach,
     fullName: null,
     insurerName: null,