feat(coach): settings UI to review and forget what the Coach remembers

Add a 'What the Coach remembers' settings section: lists the user's
durable facts grouped by category with a learned-when stamp, forgets a
single fact or clears all (behind a confirm), and notes the rolling
conversation summary. Consumes the v1.11.1 CoachFact routes via the
query-key factory; gated on the Coach feature; localised in all six
locales. Closes the API-only gap from v1.11.1.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/lib/query-keys.ts

@@ -299,6 +299,7 @@ export const queryKeys = {
 
   featureFlags: () => ["feature-flags"] as const,
   coachPrefs: () => ["coach-prefs"] as const,
+  coachFacts: () => ["coach-facts"] as const,
 
   /**
    * v1.4.41 — admin surfaces. Pre-fix every admin section declared its