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/api/tests.py

@@ -0,0 +1,77 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from app.database import get_db
+from app.models.test import Answer, Question, Test
+from app.schemas.test import TestCreate, TestListItem, TestOut
+
+router = APIRouter(prefix="/api/tests", tags=["tests"])
+
+
+@router.get("", response_model=list[TestListItem])
+async def list_tests(db: AsyncSession = Depends(get_db)):
+    result = await db.execute(
+        select(Test)
+        .options(selectinload(Test.questions))
+        .where(Test.is_active == True)
+        .order_by(Test.created_at.desc())
+    )
+    tests = result.scalars().all()
+
+    items = []
+    for test in tests:
+        item = TestListItem.model_validate(test)
+        item.questions_count = len(test.questions)
+        items.append(item)
+
+    return items
+
+
+@router.get("/{test_id}", response_model=TestOut)
+async def get_test(test_id: int, db: AsyncSession = Depends(get_db)):
+    result = await db.execute(
+        select(Test)
+        .options(selectinload(Test.questions).selectinload(Question.answers))
+        .where(Test.id == test_id, Test.is_active == True)
+    )
+    test = result.scalar_one_or_none()
+    if not test:
+        raise HTTPException(status_code=404, detail="Тест не найден")
+    return test
+
+
+@router.post("", response_model=TestOut, status_code=201)
+async def create_test(data: TestCreate, db: AsyncSession = Depends(get_db)):
+    test = Test(
+        title=data.title,
+        description=data.description,
+        passing_score=data.passing_score,
+        time_limit=data.time_limit,
+        allow_navigation_back=data.allow_navigation_back,
+    )
+    db.add(test)
+    await db.flush()
+
+    for order, q_data in enumerate(data.questions):
+        question = Question(test_id=test.id, text=q_data.text, order=order)
+        db.add(question)
+        await db.flush()
+
+        for a_data in q_data.answers:
+            db.add(Answer(
+                question_id=question.id,
+                text=a_data.text,
+                is_correct=a_data.is_correct,
+            ))
+
+    await db.commit()
+
+    # Перезагружаем с вложенными связями
+    result = await db.execute(
+        select(Test)
+        .options(selectinload(Test.questions).selectinload(Question.answers))
+        .where(Test.id == test.id)
+    )
+    return result.scalar_one()