feat(web): two-stage questionnaires, screening result and diary by result

- Sign-in: centred ЕМИАС card without the sidebar; anonymous entry asks «Депрессия / ПТСР».
- Stage 1 is the same for everyone and follows the fixed order of the MVP questionnaire:
  PHQ-2 → trauma filter/TSQ → RUS-AUDIT-S → C-SSRS → context; stage 2 only where stage 1
  is positive. Starts without a profile.
- After stage 1 the patient sees a preliminary result (screening, not a diagnosis), stored
  with the record; it switches on the diary modules (depression / PTSD).
- Stage 2 diary: morning (sleep, sleep quality, alcohol) and evening (mood, medication,
  3 PHQ-9 items in rotation, short PCL-5); C-SSRS since last contact only under risk;
  flags on weekly means against the personal norm; scheduled full scales with change
  (remission, response, worsening).
- Questionnaire log: GET /me/{token}/results and the «Мои результаты» screen.
- Questionnaires centred without the sidebar and without scale names; «Продолжить позже»
  goes home; confirmations are toasts; free-text comments are optional.
- Demo policy config/questionnaire_demo.yaml (INTAKE_DEMO only, not a clinical approval).

ADR-012.

Refs #77

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/services/questionnaire.py

@@ -47,6 +47,7 @@ async def create_record(ctx, kind, *, task=None):
     sex = profile.sex if profile else None
     if sex is None and prior:
         sex = prior.details.get("sex")
+    day = ctx.now.astimezone(ZoneInfo(runtime.timezone)).date()
     row = QuestionnaireRecord(
         id=uuid4().hex,
         token=ctx.token,
@@ -54,7 +55,7 @@ async def create_record(ctx, kind, *, task=None):
         version=content()["version"],
         policy_version=load_policy().version,
         started_at=ctx.now,
-        day=ctx.now.astimezone(ZoneInfo(runtime.timezone)).date(),
+        day=day,
         status="active",
         answers={},
         details={
@@ -69,6 +70,8 @@ async def create_record(ctx, kind, *, task=None):
             "weekly_pcl": kind == "pcl5" and bool((ctx.data.get("crisis") or {}).get("closed_at")),
             "answer_metadata": {},
             "task_id": task.id if task else None,
+            # Days since stage 1: rotates the PHQ-9 items of the depression diary module (3 a day).
+            "day_index": (day - prior.day).days if prior else 0,
         },
     )
     ctx.session.add(row)
@@ -79,7 +82,7 @@ async def create_record(ctx, kind, *, task=None):
     return row
 
 
-def save_answer(row, question, value, now):
+def save_answer(row, question, value, now, *, derived=False):
     """Anchor recall windows to administration, never to the day of a resumed answer."""
     day = row.day
     starts = {
@@ -105,8 +108,8 @@ def save_answer(row, question, value, now):
                 "period": question.period,
                 "period_start": starts[question.period].isoformat() if question.period in starts else None,
                 "period_end": day.isoformat(),
-                "source": "patient",
-                "derived": False,
+                "source": "derived" if derived else "patient",
+                "derived": derived,
             },
         },
     }
@@ -258,6 +261,16 @@ async def queue_task(session, token, kind, key, now):
     return row
 
 
+async def outstanding_task(session, token, kind):
+    return await session.scalar(
+        select(QuestionnaireTask).where(
+            QuestionnaireTask.token == token,
+            QuestionnaireTask.kind == kind,
+            QuestionnaireTask.status.in_(("pending", "active")),
+        )
+    )
+
+
 async def lock_patient(session, token):
     # PostgreSQL serializes callbacks from different workers. SQLite tests additionally
     # use the engine's in-process lock. Consent and answers share this transaction.