feat(api): align routine context windows with recent skin history

backend/innercontext/api/routines.py

@@ -49,6 +49,9 @@ from innercontext.validators.routine_validator import RoutineValidationContext
 
 logger = logging.getLogger(__name__)
 
+HISTORY_WINDOW_DAYS = 5
+SNAPSHOT_FALLBACK_DAYS = 14
+
 
 def _build_response_metadata(session: Session, log_id: Any) -> ResponseMetadata | None:
     """Build ResponseMetadata from AICallLog for Phase 3 observability."""
@@ -284,12 +287,58 @@ def _ev(v: object) -> str:
     return str(v)
 
 
-def _build_skin_context(session: Session) -> str:
+def _get_recent_skin_snapshot(
+    session: Session,
+    reference_date: date,
+    window_days: int = HISTORY_WINDOW_DAYS,
+    fallback_days: int = SNAPSHOT_FALLBACK_DAYS,
+) -> SkinConditionSnapshot | None:
+    window_cutoff = reference_date - timedelta(days=window_days)
+    fallback_cutoff = reference_date - timedelta(days=fallback_days)
+
     snapshot = session.exec(
-        select(SkinConditionSnapshot).order_by(
-            col(SkinConditionSnapshot.snapshot_date).desc()
-        )
+        select(SkinConditionSnapshot)
+        .where(SkinConditionSnapshot.snapshot_date <= reference_date)
+        .where(SkinConditionSnapshot.snapshot_date >= window_cutoff)
+        .order_by(col(SkinConditionSnapshot.snapshot_date).desc())
     ).first()
+    if snapshot is not None:
+        return snapshot
+
+    return session.exec(
+        select(SkinConditionSnapshot)
+        .where(SkinConditionSnapshot.snapshot_date <= reference_date)
+        .where(SkinConditionSnapshot.snapshot_date >= fallback_cutoff)
+        .order_by(col(SkinConditionSnapshot.snapshot_date).desc())
+    ).first()
+
+
+def _get_latest_skin_snapshot_within_days(
+    session: Session,
+    reference_date: date,
+    max_age_days: int = SNAPSHOT_FALLBACK_DAYS,
+) -> SkinConditionSnapshot | None:
+    cutoff = reference_date - timedelta(days=max_age_days)
+    return session.exec(
+        select(SkinConditionSnapshot)
+        .where(SkinConditionSnapshot.snapshot_date <= reference_date)
+        .where(SkinConditionSnapshot.snapshot_date >= cutoff)
+        .order_by(col(SkinConditionSnapshot.snapshot_date).desc())
+    ).first()
+
+
+def _build_skin_context(
+    session: Session,
+    reference_date: date,
+    window_days: int = HISTORY_WINDOW_DAYS,
+    fallback_days: int = SNAPSHOT_FALLBACK_DAYS,
+) -> str:
+    snapshot = _get_recent_skin_snapshot(
+        session,
+        reference_date=reference_date,
+        window_days=window_days,
+        fallback_days=fallback_days,
+    )
     if snapshot is None:
         return "SKIN CONDITION: no data\n"
     ev = _ev
@@ -369,10 +418,15 @@ def _build_upcoming_grooming_context(
     return "\n".join(lines) + "\n"
 
 
-def _build_recent_history(session: Session) -> str:
-    cutoff = date.today() - timedelta(days=7)
+def _build_recent_history(
+    session: Session,
+    reference_date: date,
+    window_days: int = HISTORY_WINDOW_DAYS,
+) -> str:
+    cutoff = reference_date - timedelta(days=window_days)
     routines = session.exec(
         select(Routine)
+        .where(Routine.routine_date <= reference_date)
         .where(Routine.routine_date >= cutoff)
         .order_by(col(Routine.routine_date).desc())
     ).all()
@@ -672,14 +726,14 @@ def suggest_routine(
     session: Session = Depends(get_session),
 ):
     weekday = data.routine_date.weekday()
-    skin_ctx = _build_skin_context(session)
+    skin_ctx = _build_skin_context(session, reference_date=data.routine_date)
     profile_ctx = build_user_profile_context(session, reference_date=data.routine_date)
     upcoming_grooming_ctx = _build_upcoming_grooming_context(
         session,
         start_date=data.routine_date,
         days=7,
     )
-    history_ctx = _build_recent_history(session)
+    history_ctx = _build_recent_history(session, reference_date=data.routine_date)
     day_ctx = _build_day_context(data.leaving_home)
     available_products = _get_available_products(
         session,
@@ -848,10 +902,10 @@ def suggest_routine(
     )
 
     # Get skin snapshot for barrier state
-    stmt = select(SkinConditionSnapshot).order_by(
-        col(SkinConditionSnapshot.snapshot_date).desc()
+    skin_snapshot = _get_latest_skin_snapshot_within_days(
+        session,
+        reference_date=data.routine_date,
     )
-    skin_snapshot = session.exec(stmt).first()
 
     # Build validation context
     products_by_id = {p.id: p for p in available_products}
@@ -923,9 +977,9 @@ def suggest_batch(
         {(data.from_date + timedelta(days=i)).weekday() for i in range(delta)}
     )
     profile_ctx = build_user_profile_context(session, reference_date=data.from_date)
-    skin_ctx = _build_skin_context(session)
+    skin_ctx = _build_skin_context(session, reference_date=data.from_date)
     grooming_ctx = _build_grooming_context(session, weekdays=weekdays)
-    history_ctx = _build_recent_history(session)
+    history_ctx = _build_recent_history(session, reference_date=data.from_date)
     batch_products = _get_available_products(
         session,
         include_minoxidil=data.include_minoxidil_beard,
@@ -1030,10 +1084,10 @@ def suggest_batch(
         )
 
     # Get skin snapshot for barrier state
-    stmt = select(SkinConditionSnapshot).order_by(
-        col(SkinConditionSnapshot.snapshot_date).desc()
+    skin_snapshot = _get_latest_skin_snapshot_within_days(
+        session,
+        reference_date=data.from_date,
     )
-    skin_snapshot = session.exec(stmt).first()
 
     # Build validation context
     products_by_id = {p.id: p for p in batch_products}