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/alembic/versions/001_init.py

@@ -0,0 +1,62 @@
+"""init
+
+Revision ID: 001
+Revises:
+Create Date: 2026-03-21
+
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "001"
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "tests",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("title", sa.String(255), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("passing_score", sa.Integer(), nullable=False),
+        sa.Column("time_limit", sa.Integer(), nullable=True),
+        sa.Column("allow_navigation_back", sa.Boolean(), nullable=False, server_default="true"),
+        sa.Column("is_active", sa.Boolean(), nullable=False, server_default="true"),
+        sa.Column("version", sa.Integer(), nullable=False, server_default="1"),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("now()"),
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+    op.create_table(
+        "questions",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("test_id", sa.Integer(), sa.ForeignKey("tests.id"), nullable=False),
+        sa.Column("text", sa.Text(), nullable=False),
+        sa.Column("order", sa.Integer(), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+    op.create_table(
+        "answers",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column(
+            "question_id", sa.Integer(), sa.ForeignKey("questions.id"), nullable=False
+        ),
+        sa.Column("text", sa.Text(), nullable=False),
+        sa.Column("is_correct", sa.Boolean(), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("answers")
+    op.drop_table("questions")
+    op.drop_table("tests")