Merge branch 'feat/session-signals'

Сигналы реестра занятий: очередь, повторные отказы, курсант не на связи

backend/app/api/http/sessions.py

@@ -8,6 +8,7 @@ import logging
 import time
 from collections.abc import AsyncIterator
 from datetime import UTC, datetime
+from typing import Literal
 from uuid import UUID
 
 from fastapi import APIRouter, Depends, HTTPException, Query, Request, Response
@@ -23,8 +24,8 @@ from app.db.base import get_session
 from app.db.models import Group, Score, Session, Trainee
 from app.domain.events import Exercise, SessionMode, SessionReport
 from app.domain.roles import Role
-from app.domain.statuses import SERVICE_STATUS_LABELS, StationSnapshot, current
+from app.domain.statuses import SERVICE_STATUS_LABELS, DdsQueueCard, StationSnapshot, current
-from app.domain.timers import TimerCode
+from app.domain.timers import TimerCode, TimerState
 from app.scoring.export import to_csv, to_pdf
 from app.scoring.report import build as build_report
 from app.session.access import can_access
@@ -32,6 +33,7 @@ from app.session.checkpoint import load_state
 from app.session.finish import override_score
 from app.session.score import scoring_scenario
 from app.session.hub import hub
+from app.session.state import SessionState
 from app.session.store import ScoreOverridden, apply_score_override
 from app.voice.recording import recording_path
 
@@ -86,6 +88,15 @@ class DdsHistoryOut(BaseModel):
     recipient_services: list[str] = []
 
 
+class Signal(BaseModel):
+    """Одна строка колонки сигналов реестра. Цвет несёт смысл только через
+    `severity`; текст обязателен и не заменяется цветом."""
+
+    kind: Literal["backlog", "refusals", "offline"]
+    severity: TimerState
+    text: str
+
+
 class ActiveSessionOut(BaseModel):
     session_id: UUID
     trainee_name: str | None
@@ -101,6 +112,8 @@ class ActiveSessionOut(BaseModel):
     dds_work_overdue_cards: int
     dds_statuses: dict[str, str]
     dds_snapshot: StationSnapshot | None = None
+    signals: list[Signal] = []
+    presence_known: bool = True
 
 
 def _out(session) -> SessionOut:
@@ -184,6 +197,52 @@ async def dds_history(
     return result
 
 
+def _signals(
+    state: SessionState, queue: list[DdsQueueCard], now: datetime, *, live: bool
+) -> list[Signal]:
+    """Сигналы реестра: очередь, повторные отказы, курсант не на связи.
+
+    Не завязаны на паузу занятия (`session.pause`, если появится) — очередь,
+    отказы и присутствие сокета не читают таймеры. Присутствие — по наличию
+    подписчика в хабе этого узла; окно нужно, чтобы короткий разрыв
+    соединения не сразу считался потерей связи курсанта.
+
+    `live=False` — снимок чужого узла: его сокеты здесь не видны, поэтому
+    присутствие неизвестно. Чтение реестра не меняет состояние занятия.
+    """
+    settings = get_settings()
+    signals: list[Signal] = []
+    # Необработанная — без первичного статуса: он останавливает норматив
+    # DDS_ACK. Принятая или отклонённая карточка висит в очереди до
+    # «Следующей», но реакции курсанта уже не ждёт.
+    pending = sum(not card.timer_stopped for card in queue)
+    if pending >= settings.signal_backlog_threshold:
+        signals.append(Signal(
+            kind="backlog", severity=TimerState.WARN,
+            text=f"Очередь: {pending} необработанных карточек",
+        ))
+    if state.consecutive_refusals >= settings.signal_refusals_threshold:
+        signals.append(Signal(
+            kind="refusals", severity=TimerState.WARN,
+            text=f"Подряд отказов: {state.consecutive_refusals}",
+        ))
+    if live:
+        connected = (
+            hub.station_connected(state.session_id) if state.dds_phase
+            else hub.trainee_connected(state.session_id)
+        )
+        offline_seconds = (
+            (now - (state.socket_last_seen_at or state.started_at)).total_seconds()
+            if (state.socket_last_seen_at or state.started_at) is not None else 0
+        )
+        if not connected and offline_seconds >= settings.signal_offline_window_seconds:
+            signals.append(Signal(
+                kind="offline", severity=TimerState.VIOLATED,
+                text=f"Курсант не на связи {int(offline_seconds)} с",
+            ))
+    return sorted(signals, key=lambda signal: signal.severity is not TimerState.VIOLATED)
+
+
 @router.get("/active", response_model=list[ActiveSessionOut])
 async def active(
     request: Request,
@@ -197,6 +256,9 @@ async def active(
         state.session_id: state
         for state in hub.active_sessions(who.login)
     }
+    #: Снимки без живой записи в хабе этого узла — чужой узел или сессия,
+    #: ожидающая восстановления. Её сокеты нельзя проверить этим процессом.
+    checkpoint_only: set[UUID] = set()
     if db is not None:
         rows = (
             await db.scalars(
@@ -225,11 +287,12 @@ async def active(
             state.owner_login = row.owner_login
             if not state.ended:
                 states[state.session_id] = state
+                checkpoint_only.add(state.session_id)
 
     for state in states.values():
         elapsed = (max(0, int((now - state.started_at).total_seconds()))
                    if state.started_at else 0)
-        station = state.station_snapshot() if state.exercise is Exercise.DDS else None
+        station = state.station_snapshot() if state.dds_phase else None
         queue = station.queue_cards if station else []
         card = state.desk.active
         status_log = card.status_log if card is not None else []
@@ -262,6 +325,8 @@ async def active(
             ),
             dds_statuses=latest_statuses,
             dds_snapshot=station,
+            signals=_signals(state, queue, now, live=state.session_id not in checkpoint_only),
+            presence_known=state.session_id not in checkpoint_only,
         ))
     return result
 

backend/app/api/ws/call.py

@@ -14,7 +14,7 @@ from uuid import UUID, uuid4
 from fastapi import APIRouter, WebSocket, WebSocketDisconnect
 from pydantic import TypeAdapter, ValidationError
 
-from app.api.ws.session import pump, run_command, session_socket
+from app.api.ws.session import close_fenced, pump, run_command, session_socket
 from app.domain.events import (
     BgStart,
     CallEnded,
@@ -390,9 +390,14 @@ async def call(ws: WebSocket, session_id: UUID) -> None:
     )
     if entered is None:
         return
-    _who, state = entered
+    who, state = entered
 
-    with hub.trainee(session_id) as queue:
+    async with hub.trainee_socket(
+        session_id, station=False, trainee=who.role is Role.TRAINEE,
+    ) as queue:
+        if hub.is_lease_fenced(session_id):
+            await close_fenced(ws)
+            return
         if state.exercise is Exercise.CARD:
             from app.api.ws.control import card_briefing
 

backend/app/api/ws/control.py

@@ -104,6 +104,7 @@ def _build_state(session_id: UUID, event, who, scenario, scenarios,
         dds_service=identity.service or event.dds_service,
         attempt=identity.attempt,
         criteria=event.criteria,
+        socket_last_seen_at=now_utc(),
     )
     state.timers.limits[TimerCode.DDS_ACK] = event.criteria.decision_time_limit_seconds * 1000
     state.timers.limits[TimerCode.CARD_FILL] = event.criteria.card_fill_time_limit_seconds * 1000

backend/app/api/ws/station.py

@@ -17,7 +17,7 @@ from uuid import UUID
 from fastapi import APIRouter, WebSocket, WebSocketDisconnect
 from pydantic import TypeAdapter, ValidationError
 
-from app.api.ws.session import pump, run_command, session_socket
+from app.api.ws.session import close_fenced, pump, run_command, session_socket
 from app.domain.events import (
     CallEndReason,
     ErrorEvent,
@@ -59,9 +59,14 @@ async def station(ws: WebSocket, session_id: UUID, role: str = "dds") -> None:
     entered = await session_socket(ws, session_id, (Role.INSTRUCTOR, Role.TRAINEE))
     if entered is None:
         return
-    _who, state = entered
+    who, state = entered
 
-    with hub.station(session_id) as queue:
+    async with hub.trainee_socket(
+        session_id, station=True, trainee=who.role is Role.TRAINEE,
+    ) as queue:
+        if hub.is_lease_fenced(session_id):
+            await close_fenced(ws)
+            return
         sender = asyncio.create_task(pump(ws, queue))
         try:
             # Карточка, переданная до подключения станции, не теряется:

backend/app/config.py

@@ -120,6 +120,11 @@ class Settings(BaseSettings):
     def limit_ms(self, code: TimerCode) -> int:
         return self.timer_limits_ms.get(code, NORMATIVES[code].limit_ms)
 
+    # Пороги сигналов реестра живых занятий (пульт преподавателя).
+    signal_backlog_threshold: int = Field(default=4, ge=1)
+    signal_refusals_threshold: int = Field(default=2, ge=1)
+    signal_offline_window_seconds: int = Field(default=45, ge=1)
+
     def validate_deployment_security(self) -> None:
         """Reject known development authentication defaults on a production app."""
         if self.app_env != "production":

backend/app/session/dds.py

@@ -446,6 +446,7 @@ class DdsDesk(BaseModel):
                             services[0], ServiceStatus.ACCEPTED, command.comment,
                             author="диспетчер",
                         )
+                        session.consecutive_refusals = 0
                     except StatusError:
                         pass  # статус уже стоит: повторное нажатие ничего не меняет
             case "card.status":
@@ -462,6 +463,13 @@ class DdsDesk(BaseModel):
                 # Первичный статус останавливает норматив 30 секунд.
                 if command.status in PRIMARY:
                     card.on_event("card.ack")
+                    # Сигнал реестра "повторные отказы" считает подряд идущие
+                    # отказы, а не сумму за занятие.
+                    session.consecutive_refusals = (
+                        session.consecutive_refusals + 1
+                        if command.status is ServiceStatus.DECLINED
+                        else 0
+                    )
                 if command.status in {
                     ServiceStatus.COMPLETED, ServiceStatus.DECLINED, ServiceStatus.REFUSED,
                 }:

backend/app/session/hub.py

@@ -24,6 +24,7 @@ from app.domain.events import (
 )
 from app.session.state import SessionState
 from app.session.store import MemorySessionStore, Record, SessionLeaseLost, SessionStore
+from app.session.timers import now_utc
 
 #: Очередь одного подписчика. Медленный наблюдатель не тормозит занятие:
 #: очередь ограничена, переполнение роняет соединение, а не сессию.
@@ -53,6 +54,9 @@ class SessionHub:
         self._observers: dict[UUID, set[asyncio.Queue]] = {}
         self._trainees: dict[UUID, set[asyncio.Queue]] = {}
         self._stations: dict[UUID, set[asyncio.Queue]] = {}
+        self._trainee_calls: dict[UUID, set[asyncio.Queue]] = {}
+        self._trainee_stations: dict[UUID, set[asyncio.Queue]] = {}
+        self._pending_adoptions: dict[UUID, SessionState] = {}
         self._tickers: dict[UUID, asyncio.Task] = {}
         # Задачи, порождённые внутри операции, наследуют контекст; после
         # закрытия операции их события идут напрямую (`_Operation.open`).
@@ -116,6 +120,7 @@ class SessionHub:
 
     def drop(self, session_id: UUID) -> None:
         self._sessions.pop(session_id, None)
+        self._pending_adoptions.pop(session_id, None)
         self.stop_ticker(session_id)
 
     def live_count(self) -> int:
@@ -135,9 +140,10 @@ class SessionHub:
         if not self.store.persistent:
             return 0
         restored = await self.store.restore_active()
+        adopted = 0
         for state in restored:
-            self._adopt(state)
+            adopted += await self._adopt(state)
-        return len(restored)
+        return adopted
 
     async def maintain_lease(self) -> None:
         """Один оборот супервизора: продлить свои lease, подхватить просроченные чужие.
@@ -154,6 +160,18 @@ class SessionHub:
                 log.warning("продление lease занятия %s не удалось", state.session_id,
                             exc_info=True)
                 await self.fence(state)
+        for state in list(self._pending_adoptions.values()):
+            try:
+                await self.store.commit(state)
+            except SessionLeaseLost:
+                self._pending_adoptions.pop(state.session_id, None)
+            except Exception:
+                log.warning("повторное сохранение занятия %s после takeover не удалось",
+                            state.session_id, exc_info=True)
+            else:
+                self._pending_adoptions.pop(state.session_id, None)
+                self.register(state)
+                self.start_ticker(state.session_id)
         try:
             claimed = await self.store.claim_expired()
         except Exception:  # следующий оборот попробует снова
@@ -163,17 +181,32 @@ class SessionHub:
             current = self._sessions.get(state.session_id)
             if current is not None and not current.lease_fenced:
                 continue
-            self._adopt(state)
+            await self._adopt(state)
 
     async def supervise_lease(self, interval: float) -> None:
         while True:
             await asyncio.sleep(interval)
             await self.maintain_lease()
 
-    def _adopt(self, state: SessionState) -> None:
+    async def _adopt(self, state: SessionState) -> bool:
         self.stop_ticker(state.session_id)
+        if state.socket_connected_at_checkpoint:
+            # Разрыв произошёл при потере узла; старое время подключения не
+            # доказывает, что курсант отсутствовал всё это время.
+            state.socket_last_seen_at = now_utc()
+            state.socket_connected_at_checkpoint = False
+            try:
+                await self.store.commit(state)
+            except SessionLeaseLost:
+                return False
+            except Exception:
+                log.exception("не удалось сохранить присутствие после takeover %s", state.session_id)
+                self._pending_adoptions[state.session_id] = state
+                return False
+        self._pending_adoptions.pop(state.session_id, None)
         self.register(state)
         self.start_ticker(state.session_id)
+        return True
 
     async def save_all(self) -> None:
         """Снимок живых занятий при остановке узла: следующий владелец продолжит с него."""
@@ -285,6 +318,44 @@ class SessionHub:
     def station(self, session_id: UUID):
         return self._subscribe(self._stations, session_id)
 
+    async def _record_presence(self, session_id: UUID, *, station: bool) -> None:
+        state = self.get(session_id)
+        if state is None or state.ended or state.dds_phase != station:
+            return
+        async with self.operation(session_id):
+            state.socket_last_seen_at = now_utc()
+            present = self._trainee_stations if station else self._trainee_calls
+            state.socket_connected_at_checkpoint = bool(present.get(session_id))
+
+    @contextlib.asynccontextmanager
+    async def trainee_socket(
+        self, session_id: UUID, *, station: bool, trainee: bool,
+    ) -> AsyncIterator[asyncio.Queue]:
+        """Учесть только сокет курсанта; вещание преподавателю остаётся общим."""
+        registry = self._stations if station else self._trainees
+        presence = self._trainee_stations if station else self._trainee_calls
+        with self._subscribe(registry, session_id) as queue:
+            if trainee:
+                presence.setdefault(session_id, set()).add(queue)
+            try:
+                if trainee:
+                    try:
+                        await self._record_presence(session_id, station=station)
+                    except Exception:
+                        if not self.is_lease_fenced(session_id):
+                            raise
+                yield queue
+            finally:
+                if trainee:
+                    presence[session_id].discard(queue)
+                    if not presence[session_id]:
+                        presence.pop(session_id)
+                    try:
+                        await self._record_presence(session_id, station=station)
+                    except Exception:
+                        if not self.is_lease_fenced(session_id):
+                            raise
+
     # ── вещание ──
 
     @staticmethod
@@ -314,6 +385,12 @@ class SessionHub:
     def observer_count(self, session_id: UUID) -> int:
         return len(self._observers.get(session_id, set()))
 
+    def station_connected(self, session_id: UUID) -> bool:
+        return bool(self._trainee_stations.get(session_id))
+
+    def trainee_connected(self, session_id: UUID) -> bool:
+        return bool(self._trainee_calls.get(session_id))
+
     # ── такт таймеров ──
 
     def start_ticker(self, session_id: UUID) -> None:

backend/app/session/state.py

@@ -124,6 +124,15 @@ class PersistedSession(BaseModel):
     #: a lost WebSocket acknowledgement cannot apply an operation twice.
     processed_station_commands: list[str] = Field(default_factory=list)
     text_revealed_facts: dict[str, str] = Field(default_factory=dict)
+    #: Подряд идущих первичных отказов без принятой карточки между ними —
+    #: сигнал реестра преподавателя, не влияет на балл.
+    consecutive_refusals: int = 0
+    #: Последнее подключение/отключение сокета курсанта или начало фазы ДДС.
+    #: Сохраняется вместе с занятием, чтобы чтение реестра не меняло состояние.
+    socket_last_seen_at: datetime | None = None
+    #: На момент последнего checkpoint курсант был подключён на текущем АРМ.
+    #: После аварии узла момент потери связи неизвестен: окно начинается при takeover.
+    socket_connected_at_checkpoint: bool = False
 
     @field_validator("processed_station_commands")
     @classmethod
@@ -206,6 +215,9 @@ class SessionState(PersistedSession):
         self.dispatched_at = now_utc()
         if self.exercise is Exercise.CALL:
             self._receive_call_card()
+        if self.handoff_to_dds:
+            self.socket_last_seen_at = self.dispatched_at
+            self.socket_connected_at_checkpoint = False
         return self.dispatched_card
 
     def _receive_call_card(self) -> None:

backend/tests/test_checkpoint_model.py

@@ -161,6 +161,9 @@ def full_state() -> SessionState:
         resolve_comment="передано в другой регион",
         processed_station_commands=[str(uuid4())],
         text_revealed_facts={"f_address": "улица Ленина, 14"},
+        consecutive_refusals=2,
+        socket_last_seen_at=AT,
+        socket_connected_at_checkpoint=True,
     )
 
 

backend/tests/test_session_signals.py

@@ -0,0 +1,517 @@
+"""Колонка сигналов реестра: очередь, повторные отказы, курсант не на связи."""
+
+import asyncio
+import time
+from datetime import UTC, datetime, timedelta
+from uuid import uuid4
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy.engine.result import IteratorResult, SimpleResultMetaData
+from starlette.websockets import WebSocketDisconnect
+
+from app.api.auth import Principal
+from app.api.http import sessions as sessions_http
+from app.api.ws import session as session_ws
+from app.config import get_settings
+from app.db.models import Session
+from app.domain.events import Exercise, SessionMode
+from app.domain.roles import Role
+from app.main import app
+from app.session.checkpoint import dump_state, load_state
+from app.session import hub as hub_module
+from app.session.hub import SessionHub, hub
+from app.session.state import SessionState
+from app.session.store import MemorySessionStore
+
+POOL = ["fire-apartment-l2", "t01-1-fire-container"]
+
+
+@pytest.fixture
+def client(monkeypatch):
+    monkeypatch.setenv("DEV_AUTH_BYPASS", "true")
+    get_settings.cache_clear()
+
+    async def audit_override(*_args, **_kwargs):
+        return None
+
+    async def optional_session_override():
+        yield None
+
+    monkeypatch.setattr(sessions_http, "audit_required", audit_override)
+    monkeypatch.setitem(
+        app.dependency_overrides, sessions_http.optional_session, optional_session_override
+    )
+    try:
+        with TestClient(app) as test_client:
+            test_client.post("/api/auth/dev-token")
+            hub.store = MemorySessionStore()
+            before = set(hub._sessions)
+            try:
+                yield test_client
+            finally:
+                for session_id in set(hub._sessions) - before:
+                    hub.drop(session_id)
+    finally:
+        get_settings.cache_clear()
+
+
+def wait_for(predicate, timeout=3):
+    end = time.monotonic() + timeout
+    while time.monotonic() < end:
+        value = predicate()
+        if value:
+            return value
+        time.sleep(0.02)
+    raise AssertionError("состояние не обновилось")
+
+
+def read_until(socket, wanted):
+    received = []
+    for _ in range(20):
+        event = socket.receive_json()
+        received.append(event["type"])
+        if event["type"] == wanted:
+            return event
+    raise AssertionError(f"событие {wanted} не пришло; получены: {received}")
+
+
+def start_two_card_dds(client, scenario_ids=POOL):
+    session_id = uuid4()
+    context = client.websocket_connect(f"/ws/control/{session_id}")
+    control = context.__enter__()
+    control.send_json({
+        "type": "scenario.start",
+        "scenario_id": POOL[0],
+        "trainee": "Иванов",
+        "mode": "training",
+        "exercise": "dds",
+        "random_scenario_ids": scenario_ids,
+    })
+    wait_for(lambda: hub.get(session_id))
+    return session_id, control
+
+
+def start_card_handoff(client):
+    session_id = uuid4()
+    context = client.websocket_connect(f"/ws/control/{session_id}")
+    control = context.__enter__()
+    control.send_json({
+        "type": "scenario.start", "scenario_id": POOL[0], "trainee": "Иванов",
+        "mode": "training", "exercise": "card", "handoff_to_dds": True,
+        "scenario_ids": POOL,
+    })
+    wait_for(lambda: hub.get(session_id))
+    return session_id, control
+
+
+def start_call(client):
+    session_id = uuid4()
+    context = client.websocket_connect(f"/ws/control/{session_id}")
+    control = context.__enter__()
+    control.send_json({
+        "type": "scenario.start", "scenario_id": POOL[0], "trainee": "Иванов",
+        "mode": "training", "exercise": "call",
+    })
+    wait_for(lambda: hub.get(session_id))
+    return session_id, control
+
+
+def row_for(client, session_id):
+    rows = client.get("/api/sessions/active").json()
+    return next(item for item in rows if item["session_id"] == str(session_id))
+
+
+def signal_kinds(row):
+    return {signal["kind"] for signal in row["signals"]}
+
+
+def assigned_trainee(state, monkeypatch):
+    state.trainee_id = uuid4()
+    who = Principal(login="курсант", full_name="Курсант", role=Role.TRAINEE,
+                    trainee_id=state.trainee_id)
+    monkeypatch.setattr(session_ws, "principal_of", lambda _ws: who)
+
+
+def registry_time(monkeypatch, since, seconds):
+    class Clock(datetime):
+        @classmethod
+        def now(cls, tz=None):
+            return since + timedelta(seconds=seconds)
+
+    monkeypatch.setattr(sessions_http, "datetime", Clock)
+
+
+def test_signal_backlog_when_queue_reaches_threshold(client, monkeypatch):
+    monkeypatch.setenv("SIGNAL_BACKLOG_THRESHOLD", "2")
+    get_settings.cache_clear()
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        assert len(state.desk.cards) == 2, "оба билета должны прийти сразу без интервала"
+        row = row_for(client, session_id)
+        assert row["dds_open_cards"] == 2
+        assert "backlog" in signal_kinds(row)
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_declined_card_leaves_backlog(client, monkeypatch):
+    monkeypatch.setenv("SIGNAL_BACKLOG_THRESHOLD", "2")
+    get_settings.cache_clear()
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        first_card = state.desk.ordered()[0]
+        with client.websocket_connect(f"/ws/station/{session_id}?role=dds") as station:
+            read_until(station, "station.state")
+            station.send_json({
+                "type": "card.status", "service": state.card_services(first_card)[0],
+                "status": "declined", "comment": "не наш адрес, передано в УК",
+            })
+            read_until(station, "station.state")
+        row = row_for(client, session_id)
+        assert row["dds_open_cards"] == 2, "отклонённая карточка ждёт «Следующей» на пульте"
+        assert "backlog" not in signal_kinds(row)
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_signal_refusals_after_two_consecutive_declines(client):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        first_card, second_card = state.desk.ordered()
+        with client.websocket_connect(f"/ws/station/{session_id}?role=dds") as station:
+            read_until(station, "station.state")
+            first_service = state.card_services(first_card)[0]
+            station.send_json({
+                "type": "card.status", "service": first_service, "status": "declined",
+                "comment": "не наш адрес, передано в УК",
+            })
+            read_until(station, "station.state")
+
+            row = row_for(client, session_id)
+            assert "refusals" not in signal_kinds(row), "одного отказа недостаточно для сигнала"
+
+            station.send_json({"type": "card.open", "card_id": str(second_card.card_id)})
+            read_until(station, "station.state")
+            second_service = state.card_services(second_card)[0]
+            station.send_json({
+                "type": "card.status", "service": second_service, "status": "declined",
+                "comment": "не наша территория, передано в ОМВД",
+            })
+            read_until(station, "station.state")
+
+        row = row_for(client, session_id)
+        assert state.consecutive_refusals == 2
+        assert "refusals" in signal_kinds(row)
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_acceptance_clears_refusal_streak(client):
+    session_id, control = start_two_card_dds(
+        client, [*POOL, "t20-2-stroke"],
+    )
+    try:
+        state = hub.get(session_id)
+        with client.websocket_connect(f"/ws/station/{session_id}") as station:
+            read_until(station, "station.state")
+            for card in state.desk.ordered()[:2]:
+                station.send_json({"type": "card.open", "card_id": str(card.card_id)})
+                read_until(station, "station.state")
+                station.send_json({
+                    "type": "card.status", "service": state.card_services(card)[0],
+                    "status": "declined", "comment": "Не наша территория, передано дежурному",
+                })
+                read_until(station, "station.state")
+            assert state.consecutive_refusals == 2
+            third = state.desk.ordered()[2]
+            station.send_json({"type": "card.open", "card_id": str(third.card_id)})
+            read_until(station, "station.state")
+            station.send_json({
+                "type": "card.status", "service": state.card_services(third)[0],
+                "status": "accepted", "comment": "Карточка принята диспетчером",
+            })
+            read_until(station, "station.state")
+            assert state.consecutive_refusals == 0
+            assert "refusals" not in signal_kinds(row_for(client, session_id))
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_signal_offline_when_station_socket_is_closed_past_the_window(client, monkeypatch):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        assigned_trainee(state, monkeypatch)
+        with client.websocket_connect(f"/ws/station/{session_id}?role=dds") as station:
+            read_until(station, "station.state")
+            assert hub.station_connected(session_id)
+        assert not hub.station_connected(session_id)
+        disconnected_at = state.socket_last_seen_at
+        assert disconnected_at is not None
+        window = get_settings().signal_offline_window_seconds
+        registry_time(monkeypatch, disconnected_at, window - 1)
+        assert "offline" not in signal_kinds(row_for(client, session_id))
+        registry_time(monkeypatch, disconnected_at, window + 1)
+        row = row_for(client, session_id)
+        assert "offline" in signal_kinds(row)
+        assert state.socket_last_seen_at == disconnected_at, "GET реестра не должен менять занятие"
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_signal_offline_without_first_connection(client, monkeypatch):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        started = state.socket_last_seen_at
+        assert started is not None
+        registry_time(monkeypatch, started, get_settings().signal_offline_window_seconds + 1)
+        assert "offline" in signal_kinds(row_for(client, session_id))
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_call_socket_disconnection_triggers_offline(client, monkeypatch):
+    session_id, control = start_call(client)
+    try:
+        state = hub.get(session_id)
+        assigned_trainee(state, monkeypatch)
+        with client.websocket_connect(f"/ws/call/{session_id}") as call:
+            read_until(call, "call.incoming")
+            assert hub.trainee_connected(session_id)
+        assert not hub.trainee_connected(session_id)
+        disconnected_at = state.socket_last_seen_at
+        registry_time(monkeypatch, disconnected_at,
+                      get_settings().signal_offline_window_seconds + 1)
+        assert "offline" in signal_kinds(row_for(client, session_id))
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_teacher_socket_does_not_hide_offline(client, monkeypatch):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        with client.websocket_connect(f"/ws/station/{session_id}") as station:
+            read_until(station, "station.state")
+            assert not hub.station_connected(session_id)
+            registry_time(monkeypatch, state.socket_last_seen_at,
+                          get_settings().signal_offline_window_seconds + 1)
+            assert "offline" in signal_kinds(row_for(client, session_id))
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_last_of_two_trainee_sockets_starts_offline_window(client, monkeypatch):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        assigned_trainee(state, monkeypatch)
+        with client.websocket_connect(f"/ws/station/{session_id}") as first:
+            read_until(first, "station.state")
+            with client.websocket_connect(f"/ws/station/{session_id}") as second:
+                read_until(second, "station.state")
+            assert hub.station_connected(session_id)
+            registry_time(monkeypatch, state.socket_last_seen_at,
+                          get_settings().signal_offline_window_seconds + 1)
+            assert "offline" not in signal_kinds(row_for(client, session_id))
+        disconnected_at = state.socket_last_seen_at
+        registry_time(monkeypatch, disconnected_at,
+                      get_settings().signal_offline_window_seconds + 1)
+        assert "offline" in signal_kinds(row_for(client, session_id))
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_offline_window_survives_checkpoint_restore(client, monkeypatch):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        assigned_trainee(state, monkeypatch)
+        with client.websocket_connect(f"/ws/station/{session_id}") as station:
+            read_until(station, "station.state")
+        disconnected_at = state.socket_last_seen_at
+        restored = load_state(dump_state(state), datetime.now(UTC))
+        hub.drop(session_id)
+        asyncio.run(hub._adopt(restored))
+        assert restored.socket_last_seen_at == disconnected_at
+        registry_time(monkeypatch, disconnected_at,
+                      get_settings().signal_offline_window_seconds + 1)
+        assert "offline" in signal_kinds(row_for(client, session_id))
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_takeover_starts_window_when_socket_was_open(client, monkeypatch):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        assigned_trainee(state, monkeypatch)
+        with client.websocket_connect(f"/ws/station/{session_id}") as station:
+            read_until(station, "station.state")
+            assert state.socket_connected_at_checkpoint
+            snapshot = dump_state(state)
+        old_time = state.socket_last_seen_at
+        takeover_at = old_time + timedelta(minutes=10)
+        monkeypatch.setattr(hub_module, "now_utc", lambda: takeover_at)
+        restored = load_state(snapshot, datetime.now(UTC))
+
+        class CapturingStore(MemorySessionStore):
+            def __init__(self):
+                self.saved = None
+
+            async def commit(self, state, _records=()):
+                self.saved = dump_state(state)
+
+        store = CapturingStore()
+        local_hub = SessionHub(store)
+        try:
+            assert asyncio.run(local_hub._adopt(restored))
+            assert restored.socket_last_seen_at == takeover_at
+            assert not restored.socket_connected_at_checkpoint
+            assert datetime.fromisoformat(
+                store.saved["socket_last_seen_at"].replace("Z", "+00:00")
+            ) == takeover_at
+            assert store.saved["socket_connected_at_checkpoint"] is False
+        finally:
+            local_hub.stop_ticker(session_id)
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_card_handoff_uses_trainee_station_presence(client, monkeypatch):
+    session_id, control = start_card_handoff(client)
+    try:
+        state = hub.get(session_id)
+        assigned_trainee(state, monkeypatch)
+        with monkeypatch.context() as clock:
+            with client.websocket_connect(f"/ws/call/{session_id}") as call:
+                read_until(call, "card.briefing")
+                call.send_json({"type": "card.submit"})
+                read_until(call, "call.ended")
+                handoff_at = state.socket_last_seen_at
+                clock.setattr(hub_module, "now_utc", lambda: handoff_at + timedelta(minutes=1))
+        assert state.socket_last_seen_at == handoff_at, "старый call-сокет не сбрасывает окно ДДС"
+        assert state.exercise.value == "card" and state.dds_phase
+        assert state.desk.scenarios
+        with client.websocket_connect(f"/ws/station/{session_id}") as station:
+            read_until(station, "station.state")
+            registry_time(monkeypatch, state.socket_last_seen_at,
+                          get_settings().signal_offline_window_seconds + 1)
+            row = row_for(client, session_id)
+            assert row["dds_open_cards"] > 0
+            assert "offline" not in signal_kinds(row)
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_checkpoint_on_another_node_marks_presence_unknown(client, monkeypatch):
+    session_id, control = start_two_card_dds(client)
+    try:
+        state = hub.get(session_id)
+        snapshot = dump_state(state)
+        checkpoint_at = datetime.now(UTC)
+        hub.drop(session_id)
+
+        row = Session(id=session_id, owner_login="dev",
+                      live_state=snapshot, checkpoint_at=checkpoint_at)
+
+        class CheckpointDB:
+            async def scalars(self, _query):
+                return IteratorResult(SimpleResultMetaData(["Session"]), iter([(row,)])).scalars()
+
+        monkeypatch.setattr(sessions_http, "require", lambda _request, _role:
+                            Principal(login="dev", full_name="Преподаватель",
+                                      role=Role.INSTRUCTOR))
+        rows = asyncio.run(sessions_http.active(None, db=CheckpointDB()))
+        row = next(item for item in rows if item.session_id == session_id)
+        assert row.presence_known is False
+        assert "offline" not in {item.kind for item in row.signals}
+    finally:
+        hub.stop_ticker(session_id)
+        control.__exit__(None, None, None)
+
+
+def test_failed_presence_commit_does_not_leave_connected_socket():
+    class BrokenStore(MemorySessionStore):
+        async def commit(self, _state, _records=()):
+            raise OSError("test commit failure")
+
+    local_hub = SessionHub(BrokenStore())
+    state = local_hub.register(SessionState(
+        session_id=uuid4(), scenario_id="test", scenario_title="Тест", level="L1",
+        mode=SessionMode.TRAINING, exercise=Exercise.DDS,
+    ))
+
+    async def connect():
+        async with local_hub.trainee_socket(state.session_id, station=True, trainee=True):
+            assert local_hub.is_lease_fenced(state.session_id)
+
+    asyncio.run(connect())
+    assert not local_hub.station_connected(state.session_id)
+
+
+def test_failed_presence_commit_closes_station_with_fencing_code(client, monkeypatch):
+    class BrokenStore(MemorySessionStore):
+        async def commit(self, _state, _records=()):
+            raise OSError("test commit failure")
+
+    session_id, control = start_two_card_dds(client)
+    try:
+        assigned_trainee(hub.get(session_id), monkeypatch)
+        hub.store = BrokenStore()
+        with client.websocket_connect(f"/ws/station/{session_id}") as station:
+            event = station.receive_json()
+            assert event["type"] == "error" and event["code"] == "internal"
+            with pytest.raises(WebSocketDisconnect) as closed:
+                station.receive_json()
+            assert closed.value.code == 1012
+        assert not hub.station_connected(session_id)
+    finally:
+        control.__exit__(None, None, None)
+
+
+def test_takeover_retries_failed_presence_checkpoint():
+    class FlakyStore(MemorySessionStore):
+        def __init__(self):
+            self.commits = 0
+
+        async def commit(self, _state, _records=()):
+            self.commits += 1
+            if self.commits == 1:
+                raise OSError("temporary database outage")
+
+    store = FlakyStore()
+    local_hub = SessionHub(store)
+    state = SessionState(
+        session_id=uuid4(), scenario_id="test", scenario_title="Тест", level="L1",
+        mode=SessionMode.TRAINING, exercise=Exercise.DDS,
+        socket_last_seen_at=datetime.now(UTC) - timedelta(minutes=10),
+        socket_connected_at_checkpoint=True,
+    )
+
+    async def recover():
+        assert not await local_hub._adopt(state)
+        assert local_hub.get(state.session_id) is None
+        await local_hub.maintain_lease()
+        assert local_hub.get(state.session_id) is state
+        assert store.commits == 2
+        await local_hub.shutdown()
+
+    asyncio.run(recover())

frontend/src/pages/instructor/Instructor.tsx

@@ -22,6 +22,7 @@ import {
   useActiveSessions, useIncidentGroups, useReviewScenarioSubmission, useScenarioSubmissions,
   useScenarios, useSessions, useTrainees,
 } from "@/shared/api/http";
+import type { Signal } from "@/shared/api/http";
 import { sessionIdFromUrl } from "@/shared/api/session";
 import type { Level, SessionMode, SessionReport } from "@/shared/types/generated";
 
@@ -44,6 +45,12 @@ function modeLabel(mode: SessionMode): string {
   return MODES.find((item) => item.value === mode)?.label ?? mode;
 }
 
+function worstSignalSeverity(signals: Signal[]): "warn" | "violated" | null {
+  return signals.some((signal) => signal.severity === "violated")
+    ? "violated"
+    : signals.length ? "warn" : null;
+}
+
 function sessionDateLabel(value: string | null): string | null {
   if (!value) return null;
   const date = new Date(value);
@@ -338,7 +345,7 @@ export function Instructor() {
           Список ваших активных сессий обновляется автоматически каждые 2 секунды.
         </p>
         <div className="dds-table-wrap"><table className="grid">
-          <thead><tr><th>Курсант</th><th>Упражнение · карточка</th><th>Ход</th><th>ДДС</th><th>Задержки</th><th></th></tr></thead>
+          <thead><tr><th>Курсант</th><th>Упражнение · карточка</th><th>Ход</th><th>ДДС</th><th>Задержки</th><th>Сигналы</th><th></th></tr></thead>
           <tbody>
             {(activeSessions.data ?? []).map((item) => (
               <tr key={item.session_id}>
@@ -383,12 +390,18 @@ export function Instructor() {
                     ? `Просрочено: первичная реакция ${item.dds_overdue_cards}; отработка карточки ${item.dds_work_overdue_cards}`
                     : "Нормативы не нарушены"}
                 </td>
+                <td className={worstSignalSeverity(item.signals) ? `state-${worstSignalSeverity(item.signals)}` : item.presence_known ? "state-ok" : undefined}>
+                  {item.signals.length
+                    ? item.signals.map((signal) => <span key={signal.kind}>{signal.text}<br /></span>)
+                    : item.presence_known ? "Сигналов нет" : null}
+                  {!item.presence_known && <span>Связь курсанта не проверена</span>}
+                </td>
                 <td><button type="button" onClick={() => openActiveSession(item)}>
                   {sessionId === item.session_id ? "Открыто" : "Наблюдать"}
                 </button></td>
               </tr>
             ))}
-            {!activeSessions.data?.length && <tr><td colSpan={6}>
+            {!activeSessions.data?.length && <tr><td colSpan={7}>
               {activeSessions.isLoading ? "Загружаем активные занятия…" : "Активных занятий пока нет."}
             </td></tr>}
           </tbody>

frontend/src/shared/api/http.ts

@@ -3,7 +3,9 @@
 
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 
-import type { Level, SessionMode, SessionReport, StationSnapshot } from "@/shared/types/generated";
+import type {
+  Level, SessionMode, SessionReport, StationSnapshot, TimerState,
+} from "@/shared/types/generated";
 
 import { reportErrorMessage, reportRetryDelay, shouldRetryReport } from "./report.mjs";
 
@@ -94,6 +96,12 @@ export interface SessionInfo {
   end_reason: string | null;
 }
 
+export interface Signal {
+  kind: "backlog" | "refusals" | "offline";
+  severity: TimerState;
+  text: string;
+}
+
 export interface ActiveSessionInfo {
   session_id: string;
   trainee_name: string | null;
@@ -109,6 +117,8 @@ export interface ActiveSessionInfo {
   dds_work_overdue_cards: number;
   dds_statuses: Record<string, string>;
   dds_snapshot: StationSnapshot | null;
+  signals: Signal[];
+  presence_known: boolean;
 }
 
 export const useActiveSessions = () =>