Implement duty schedule import functionality and enhance user management

- Added a new command `/import_duty_schedule` for importing duty schedules via JSON, restricted to admin users.
- Introduced a two-step import process: specifying handover time and uploading a JSON file.
- Updated the database schema to allow `telegram_user_id` to be nullable for user creation by full name.
- Implemented repository functions for user management, including `get_or_create_user_by_full_name` and `delete_duties_in_range`.
- Enhanced README documentation with details on the new import command and JSON format requirements.
- Added comprehensive tests for the duty schedule parser and integration tests for the import functionality.

tests/test_repository_duty_range.py

@@ -0,0 +1,93 @@
+"""Tests for delete_duties_in_range and get_or_create_user_by_full_name."""
+
+import pytest
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+from db.models import Base, User, Duty
+from db.repository import (
+    delete_duties_in_range,
+    get_or_create_user_by_full_name,
+    get_duties,
+    insert_duty,
+)
+
+
+@pytest.fixture
+def session():
+    engine = create_engine("sqlite:///:memory:", connect_args={"check_same_thread": False})
+    Base.metadata.create_all(engine)
+    Session = sessionmaker(bind=engine, autocommit=False, autoflush=False)
+    s = Session()
+    try:
+        yield s
+    finally:
+        s.close()
+
+
+@pytest.fixture
+def user_a(session):
+    u = User(
+        telegram_user_id=None,
+        full_name="User A",
+        username=None,
+        first_name=None,
+        last_name=None,
+    )
+    session.add(u)
+    session.commit()
+    session.refresh(u)
+    return u
+
+
+def test_get_or_create_user_by_full_name_creates(session):
+    u = get_or_create_user_by_full_name(session, "Новый Пользователь")
+    assert u.id is not None
+    assert u.full_name == "Новый Пользователь"
+    assert u.telegram_user_id is None
+
+
+def test_get_or_create_user_by_full_name_returns_existing(session, user_a):
+    u = get_or_create_user_by_full_name(session, "User A")
+    assert u.id == user_a.id
+    assert u.full_name == "User A"
+
+
+def test_delete_duties_in_range_removes_only_in_range(session, user_a):
+    # Duties: 2026-02-01 06:00 - 2026-02-02 06:00; 2026-02-15 - 2026-02-16; 2026-02-28 - 2026-03-01
+    insert_duty(
+        session,
+        user_a.id,
+        "2026-02-01T06:00:00Z",
+        "2026-02-02T06:00:00Z",
+    )
+    insert_duty(
+        session,
+        user_a.id,
+        "2026-02-15T06:00:00Z",
+        "2026-02-16T06:00:00Z",
+    )
+    insert_duty(
+        session,
+        user_a.id,
+        "2026-02-28T06:00:00Z",
+        "2026-03-01T06:00:00Z",
+    )
+    deleted = delete_duties_in_range(session, user_a.id, "2026-02-10", "2026-02-20")
+    assert deleted == 1
+    remaining = get_duties(session, "2026-01-01", "2026-03-31")
+    assert len(remaining) == 2
+    starts = [d[0].start_at for d in remaining]
+    assert "2026-02-01T06:00:00Z" in starts
+    assert "2026-02-28T06:00:00Z" in starts
+    assert "2026-02-15T06:00:00Z" not in starts
+
+
+def test_delete_duties_in_range_other_user_unchanged(session, user_a):
+    user_b = get_or_create_user_by_full_name(session, "User B")
+    insert_duty(session, user_a.id, "2026-02-10T06:00:00Z", "2026-02-11T06:00:00Z")
+    insert_duty(session, user_b.id, "2026-02-10T06:00:00Z", "2026-02-11T06:00:00Z")
+    delete_duties_in_range(session, user_a.id, "2026-02-01", "2026-02-28")
+    remaining = get_duties(session, "2026-02-01", "2026-02-28")
+    assert len(remaining) == 1
+    assert remaining[0][1] == "User B"