feat(coach): add the CoachReminder episodic-memory model

Introduce a third Coach memory type alongside facts (durable traits) and
plans (standing if-then habits): a time-anchored "bring this back later"
reminder with a due moment and a done state. The free-text note is
AES-256-GCM ciphertext via the shared Bytes codec; metric, status, the
trigger fields and the dates stay plain so the sweep and the injection
picker rank and filter without a per-row decrypt.

Migration 0196 is purely additive (status and trigger_kind are app-side
closed enums, not DB enums). Register the new note_encrypted column in the
encrypted-columns registry and the rotation script so a key rotation can
never silently skip it.

prisma/migrations/0196_coach_reminder/migration.sql

@@ -0,0 +1,42 @@
+-- v1.22 (B2/B6) — Coach episodic reminder memory.
+--
+-- A time-anchored "bring this back later" intent the Coach captured from a
+-- conversation. The missing memory type between coach_facts (durable traits)
+-- and coach_plans (standing if-then habits): an episode with a due moment and
+-- a done state. The free-text note is AES-256-GCM ciphertext stored as `bytea`
+-- via the shared Bytes codec — the same shape as coach_plans.if_cue_encrypted.
+-- metric / status / trigger fields / dates / source stay plain so the daily
+-- sweep and the injection picker can rank and filter without a per-row decrypt.
+-- status (proposed | active | due | surfaced | done | dismissed) and
+-- trigger_kind (date | context) are app-side closed enums, deliberately NOT DB
+-- enums so this migration stays purely additive. Soft-delete via deleted_at.
+CREATE TABLE "coach_reminders" (
+    "id" TEXT NOT NULL,
+    "user_id" TEXT NOT NULL,
+    "note_encrypted" BYTEA NOT NULL,
+    "metric" TEXT,
+    "related_plan_id" TEXT,
+    "trigger_kind" TEXT NOT NULL DEFAULT 'date',
+    "due_at" TIMESTAMP(3),
+    "context_cue" TEXT,
+    "status" TEXT NOT NULL DEFAULT 'active',
+    "source" TEXT NOT NULL,
+    "source_conversation_id" TEXT,
+    "last_surfaced_at" TIMESTAMP(3),
+    "surface_count" INTEGER NOT NULL DEFAULT 0,
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updated_at" TIMESTAMP(3) NOT NULL,
+    "deleted_at" TIMESTAMP(3),
+
+    CONSTRAINT "coach_reminders_pkey" PRIMARY KEY ("id")
+);
+
+-- The daily sweep scans a user's active reminders whose due_at has passed; the
+-- status + deleted_at columns are part of that predicate, so the composite
+-- index lets the planner serve the sweep + the injection read index-backed.
+CREATE INDEX "coach_reminders_user_id_status_due_at_deleted_at_idx" ON "coach_reminders"("user_id", "status", "due_at", "deleted_at");
+
+-- The context-cue evaluation pass filters by trigger_kind + status per user.
+CREATE INDEX "coach_reminders_user_id_trigger_kind_status_idx" ON "coach_reminders"("user_id", "trigger_kind", "status");
+
+ALTER TABLE "coach_reminders" ADD CONSTRAINT "coach_reminders_user_id_fkey" FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;

prisma/schema.prisma

@@ -571,6 +571,7 @@ model User {
   coachConversations     CoachConversation[]
   coachFacts             CoachFact[]
   coachPlans             CoachPlan[]
+  coachReminders         CoachReminder[]
   coachUsage             CoachUsage[]
   // v1.4.25 W8d — workout passthrough (Apple HKWorkout / Withings
   // getworkouts / future Strava). Schema lands now so the v1.5 iOS
@@ -3938,6 +3939,56 @@ model CoachPlan {
   @@map("coach_plans")
 }
 
+// v1.22 (B2/B6) — durable, user-scoped EPISODIC reminder memory: a
+// time-anchored "bring this back later" intent the Coach captured from a
+// conversation ("remind me about my sleep next week"). This is the middle
+// memory type that neither CoachFact (durable traits) nor CoachPlan (standing
+// if-then habits) covers — an episode with a due moment and a done state.
+//
+// The free-text note is the user's own framing, encrypted at rest (AES-256-GCM
+// via the shared Bytes codec, exactly like CoachPlan's cue/action). `metric`,
+// `status`, the trigger fields and the dates stay plain so the daily sweep and
+// the injection picker can rank / filter without paying a per-row decrypt.
+//
+// `status` is an APP-SIDE closed enum (NOT a DB enum, to keep the migration
+// purely additive): proposed | active | due | surfaced | done | dismissed.
+// `triggerKind` is likewise app-side closed: date | context. Soft-delete via
+// `deletedAt` so a "forget this" action is reversible / auditable.
+model CoachReminder {
+  id                   String    @id @default(cuid())
+  userId               String    @map("user_id")
+  // What to bring back — the user's own framing, encrypted at rest.
+  noteEncrypted        Bytes     @map("note_encrypted")
+  // Optional link to the metric / plan it concerns; plain for filtering.
+  metric               String?
+  relatedPlanId        String?   @map("related_plan_id")
+  // Trigger model — app-side closed enum (date | context). For `date`, `dueAt`
+  // carries the fire moment; for `context`, `contextCue` names a closed cue.
+  triggerKind          String    @default("date") @map("trigger_kind")
+  dueAt                DateTime? @map("due_at")
+  contextCue           String?   @map("context_cue")
+  // Lifecycle: proposed | active | due | surfaced | done | dismissed.
+  status               String    @default("active")
+  // Provenance — how it was captured (sentinel | extractor | manual | action).
+  source               String
+  sourceConversationId String?   @map("source_conversation_id")
+  lastSurfacedAt       DateTime? @map("last_surfaced_at")
+  // How many times the sweep has surfaced this without the user acting; capped
+  // before auto-dismiss so an ignored reminder cannot nag indefinitely.
+  surfaceCount         Int       @default(0) @map("surface_count")
+  createdAt            DateTime  @default(now()) @map("created_at")
+  updatedAt            DateTime  @updatedAt @map("updated_at")
+  deletedAt            DateTime? @map("deleted_at")
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  // The daily sweep scans active reminders whose dueAt has passed; the status +
+  // deleted_at columns are part of the predicate so the read stays index-backed.
+  @@index([userId, status, dueAt, deletedAt])
+  @@index([userId, triggerKind, status])
+  @@map("coach_reminders")
+}
+
 // v1.15.20 — user-authored "about me" self-description the AI surfaces
 // (Coach system prompt + daily-briefing user prompt) inject as a clearly
 // delimited, user-provided context block. 1:1 with User and lazily

scripts/rotate-encryption-key.ts

@@ -328,6 +328,16 @@ async function main() {
     results.push(await rotateBytesColumn("CoachPlan", field, prisma.coachPlan));
   }
 
+  // ───── CoachReminder (Bytes column) ─────
+  // "noteEncrypted"
+  results.push(
+    await rotateBytesColumn(
+      "CoachReminder",
+      "noteEncrypted",
+      prisma.coachReminder,
+    ),
+  );
+
   // ───── UserHealthProfile (Bytes columns) ─────
   // "aboutMeEncrypted" "conditionsEncrypted" "allergiesEncrypted"
   // "coachFocusEncrypted" "pendingQuestionsEncrypted"

src/lib/crypto/encrypted-columns.ts

@@ -112,6 +112,8 @@ export const ENCRYPTED_COLUMNS: readonly EncryptedColumn[] = [
   { model: "CoachPlan", field: "ifCueEncrypted", kind: "bytes" },
   { model: "CoachPlan", field: "thenActionEncrypted", kind: "bytes" },
   { model: "CoachPlan", field: "targetEncrypted", kind: "bytes" },
+  // v1.22 (B2/B6) — Coach episodic reminder free-text note.
+  { model: "CoachReminder", field: "noteEncrypted", kind: "bytes" },
 
   // ───── User health profile (Bytes columns) ─────
   { model: "UserHealthProfile", field: "aboutMeEncrypted", kind: "bytes" },