Add tests + fix db.py SQLite commit pattern

Tests:
- tests/test_commands.py: parse_args, extract_args, format_bounty
- tests/test_db.py: full CRUD + tracking + reminders
- tests/conftest.py: temp DB fixture
- requirements-dev.txt: pytest + pytest-asyncio

db.py fixes:
- Explicit conn.commit() after every write (SQLite row_factory
  disables implicit transaction management)
- fetchone() before commit() (can't commit while cursor open)
- Functions return dict instead of sqlite3.Row

apps/telegram-bot/tests/conftest.py

@@ -0,0 +1,27 @@
+"""Pytest fixtures for telegram-bot tests."""
+
+import sys
+import tempfile
+from pathlib import Path
+
+import pytest
+
+# Add the app directory to path so `import db` works when running pytest
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+
+@pytest.fixture(autouse=True)
+def fresh_db(monkeypatch):
+    """Replace DB_PATH with a temp file before any test runs."""
+    import db as _db
+
+    tmp = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
+    tmp_path = Path(tmp.name)
+    tmp.close()
+
+    monkeypatch.setattr(_db, "DB_PATH", tmp_path)
+    _db.init_db()
+
+    yield tmp_path
+
+    tmp_path.unlink(missing_ok=True)