feat: initial microservices project structure

Services:
- api: FastAPI gateway with JWT auth, async endpoints, WebSocket
- worker-gpu: CUDA sentence-transformers, FAISS IVFFlat, Ollama LLM
- worker-indexer: Winnowing+MinHash plagiarism detection, PDF/DOCX extraction
- worker-notifier: SMTP email notifications
- worker-gost: GOST 7.1-2003 and GOST R 7.0.5-2008 formatting

Infrastructure:
- docker-compose.yml (production) + docker-compose.dev.yml (hot reload)
- Nginx reverse proxy + WebSocket support
- PostgreSQL 16 with Alembic migrations
- Elasticsearch 8 with Russian/English analyzers
- MinIO, RabbitMQ, Redis, Ollama

Frontend:
- React 18 + Vite + TypeScript + TailwindCSS + Zustand + React Query v5
- 9 pages: Home, Search, Cabinet, Task, Check, Bibliography, Pricing, Login, Register

Scripts:
- Parser stubs: OpenAlex, КиберЛенинка, arXiv (Phase 0 - to be filled)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/api/app/core/websocket_manager.py

@@ -0,0 +1,86 @@
+"""WebSocket менеджер для real-time обновлений статуса задач."""
+
+import json
+import logging
+from typing import Any
+
+from fastapi import WebSocket
+
+logger = logging.getLogger(__name__)
+
+
+class ConnectionManager:
+    """Менеджер WebSocket соединений с поддержкой подписки на задачи."""
+
+    def __init__(self) -> None:
+        # task_id -> список активных соединений
+        self._connections: dict[str, list[WebSocket]] = {}
+
+    async def connect(self, task_id: str, websocket: WebSocket) -> None:
+        """Принять WebSocket соединение и зарегистрировать его для задачи."""
+        await websocket.accept()
+        if task_id not in self._connections:
+            self._connections[task_id] = []
+        self._connections[task_id].append(websocket)
+        logger.info(f"WebSocket подключён к задаче {task_id!r}")
+
+    def disconnect(self, task_id: str, websocket: WebSocket) -> None:
+        """Удалить соединение из реестра."""
+        if task_id in self._connections:
+            try:
+                self._connections[task_id].remove(websocket)
+            except ValueError:
+                pass
+            if not self._connections[task_id]:
+                del self._connections[task_id]
+        logger.info(f"WebSocket отключён от задачи {task_id!r}")
+
+    async def send_task_update(self, task_id: str, data: dict[str, Any]) -> None:
+        """
+        Отправить обновление статуса задачи всем подключённым клиентам.
+
+        Args:
+            task_id: ID задачи
+            data: Словарь с обновлением (status, queue_position, result и т.д.)
+        """
+        connections = self._connections.get(task_id, [])
+        if not connections:
+            return
+
+        message = json.dumps(data, ensure_ascii=False, default=str)
+        dead_connections = []
+
+        for websocket in connections:
+            try:
+                await websocket.send_text(message)
+            except Exception as e:
+                logger.warning(f"Ошибка отправки WebSocket сообщения: {e}")
+                dead_connections.append(websocket)
+
+        # Очистить мёртвые соединения
+        for ws in dead_connections:
+            self.disconnect(task_id, ws)
+
+    async def broadcast(self, data: dict[str, Any]) -> None:
+        """Отправить сообщение всем подключённым клиентам."""
+        message = json.dumps(data, ensure_ascii=False, default=str)
+        all_dead = []
+
+        for task_id, connections in self._connections.items():
+            for websocket in connections:
+                try:
+                    await websocket.send_text(message)
+                except Exception:
+                    all_dead.append((task_id, websocket))
+
+        for task_id, ws in all_dead:
+            self.disconnect(task_id, ws)
+
+    @property
+    def active_connections_count(self) -> int:
+        """Количество активных WebSocket соединений."""
+        return sum(len(conns) for conns in self._connections.values())
+
+
+# Глобальный экземпляр менеджера
+ws_manager = ConnectionManager()