feat(coach): inject durable facts into the snapshot memory block

buildCoachMemoryBlock gains a third fault-isolated sub-source — the
top-N durable facts — folded under snapshot.memory so they ride the
existing lowest-priority registration and are shed first under the
char budget. Add an EN + DE system-prompt paragraph instructing the
Coach to use facts as the user's own stated, descriptive context —
never as a diagnosis, never invented.

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

src/lib/ai/coach/memory-snapshot.ts

@@ -38,6 +38,7 @@ import {
   type BandTransition,
 } from "@/lib/insights/narrative/period-narrative";
 import type { BaselineProfile } from "@/lib/insights/derived";
+import { buildCoachFactsBlock } from "./facts";
 
 /** The period the rolling profile recalls — month is the high-signal beat. */
 const MEMORY_PERIOD: NarrativePeriod = "month";
@@ -72,6 +73,11 @@ export interface PriorNarrativeRecall {
 export interface CoachMemoryBlock {
   priorNarrative?: PriorNarrativeRecall;
   trendMemory: Record<string, TrendMemoryEntry>;
+  /**
+   * v1.11.1 — durable personal facts the Coach has learned (top-N, ranked by
+   * confidence then recency). Descriptive, never diagnostic. Absent when none.
+   */
+  facts?: Array<{ category: string; text: string }>;
 }
 
 /** Pull the headline + driver recall off the latest period narrative. */
@@ -147,11 +153,29 @@ export async function buildCoachMemoryBlock(
     // A context failure leaves trendMemory empty — never sinks the turn.
   }
 
-  if (!priorNarrative && Object.keys(trendMemory).length === 0) {
+  // Sub-source 3 (v1.11.1): durable personal facts the Coach has extracted.
+  // Fault-isolated like the others — a read/decrypt failure drops the facts
+  // sub-block and never sinks the turn.
+  let facts: Array<{ category: string; text: string }> | undefined;
+  try {
+    const factsBlock = await buildCoachFactsBlock(userId);
+    if (factsBlock && factsBlock.facts.length > 0) {
+      facts = factsBlock.facts;
+    }
+  } catch {
+    facts = undefined;
+  }
+
+  if (
+    !priorNarrative &&
+    Object.keys(trendMemory).length === 0 &&
+    !facts
+  ) {
     return null;
   }
 
   const block: CoachMemoryBlock = { trendMemory };
   if (priorNarrative) block.priorNarrative = priorNarrative;
+  if (facts) block.facts = facts;
   return block;
 }

src/lib/ai/coach/system-prompt.ts

@@ -200,6 +200,14 @@ ISO-week means.
   not clinical assessments or diagnoses — never frame a band as a
   medical finding, and lean on lower-confidence / few-day entries
   cautiously. Never recompute or second-guess the number.
+- The SNAPSHOT's "memory" block MAY carry a "facts" list — durable
+  things you have learned about this user across conversations (stable
+  preferences, conditions they have told you about, goals, constraints,
+  life context). Use them to personalise your reply and to avoid
+  re-asking what you already know. Treat each as the user's OWN stated
+  context, DESCRIPTIVE not diagnostic — never restate a "condition" fact
+  as a medical finding, and never invent a fact the block does not
+  carry. If a fact seems outdated, gently check it rather than assume.
 
 EVIDENCE BLOCK
 
@@ -471,6 +479,16 @@ ISO-Wochenmittel zusammen.
   das der SNAPSHOT nicht enthält. Der "workouts"-Block führt die
   jüngsten Einheiten plus eine Zusammenfassung je Sportart, nicht
   jede Einheit.
+- Der "memory"-Block des SNAPSHOT kann eine "facts"-Liste tragen —
+  dauerhafte Dinge, die du über diesen Nutzer gelernt hast (stabile
+  Vorlieben, vom Nutzer selbst genannte gesundheitliche Umstände,
+  Ziele, Einschränkungen, Lebenskontext). Nutze sie, um deine Antwort
+  zu personalisieren und nicht erneut zu fragen, was du schon weißt.
+  Behandle jeden Eintrag als die EIGENE Aussage des Nutzers,
+  BESCHREIBEND, nicht diagnostisch — formuliere einen "condition"-Fakt
+  nie als medizinischen Befund um und erfinde nie einen Fakt, den der
+  Block nicht enthält. Wirkt ein Fakt veraltet, frage behutsam nach,
+  statt es anzunehmen.
 
 EVIDENZ-BLOCK