feat: Sprint 1 — infrastructure + test creation

Backend:
- FastAPI + SQLAlchemy 2.0 async + Alembic
- Models: Test, Question, Answer
- API: GET /api/tests, GET /api/tests/{id}, POST /api/tests
- Pydantic validation: min 7 questions, min 3 answers, ≥1 correct

Frontend:
- React 18 + TypeScript + Vite + Ant Design + TanStack Query
- Pages: TestList, TestCreate (nested Form.List), TestDetail

Infrastructure:
- Docker Compose: db (postgres:16), backend, frontend, nginx
- Nginx: /api/ → FastAPI, / → Vite dev server with HMR
- Alembic migration 001_init: tests, questions, answers tables
- entrypoint.sh: wait for db, migrate, start uvicorn

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

backend/app/models/test.py

@@ -0,0 +1,54 @@
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, Integer, String, Text
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class Test(Base):
+    __tablename__ = "tests"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    title: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    passing_score: Mapped[int] = mapped_column(Integer, nullable=False)
+    time_limit: Mapped[int | None] = mapped_column(Integer, nullable=True)  # минуты
+    allow_navigation_back: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False)
+    is_active: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False)
+    version: Mapped[int] = mapped_column(Integer, default=1, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now()
+    )
+
+    questions: Mapped[list["Question"]] = relationship(
+        "Question", back_populates="test", cascade="all, delete-orphan"
+    )
+
+
+class Question(Base):
+    __tablename__ = "questions"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    test_id: Mapped[int] = mapped_column(Integer, ForeignKey("tests.id"), nullable=False)
+    text: Mapped[str] = mapped_column(Text, nullable=False)
+    order: Mapped[int] = mapped_column(Integer, nullable=False)
+
+    test: Mapped["Test"] = relationship("Test", back_populates="questions")
+    answers: Mapped[list["Answer"]] = relationship(
+        "Answer", back_populates="question", cascade="all, delete-orphan"
+    )
+
+
+class Answer(Base):
+    __tablename__ = "answers"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    question_id: Mapped[int] = mapped_column(
+        Integer, ForeignKey("questions.id"), nullable=False
+    )
+    text: Mapped[str] = mapped_column(Text, nullable=False)
+    is_correct: Mapped[bool] = mapped_column(Boolean, nullable=False)
+
+    question: Mapped["Question"] = relationship("Question", back_populates="answers")