Phase 1: Foundation — backend auth, frontend shell, Docker setup

Backend (FastAPI):
- App factory with async SQLAlchemy 2.0 + PostgreSQL
- Alembic migration for users and sessions tables
- JWT auth (access + refresh tokens, bcrypt passwords)
- Auth endpoints: register, login, refresh, logout, me
- Admin seed script, role-based access deps

Frontend (React + TypeScript):
- Vite + Tailwind CSS + shadcn/ui theme (health-oriented palette)
- i18n with English and Russian translations
- Zustand auth/UI stores with localStorage persistence
- Axios client with automatic token refresh on 401
- Login/register pages, protected routing
- App layout: collapsible sidebar, header with theme/language toggles
- Dashboard with placeholder stats

Infrastructure:
- Docker Compose (postgres, backend, frontend, nginx)
- Nginx reverse proxy with WebSocket support
- Dev override with hot reload

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/models/session.py

@@ -0,0 +1,22 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, String
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class Session(Base):
+    __tablename__ = "sessions"
+
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    refresh_token_hash: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
+    device_info: Mapped[str | None] = mapped_column(String(500), nullable=True)
+    ip_address: Mapped[str | None] = mapped_column(String(45), nullable=True)
+    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+
+    user: Mapped["User"] = relationship(back_populates="sessions")  # noqa: F821