feat(database): add simple session creation utility

Utility script for creating investigation database session:
- Basic asyncpg connection setup
- Session management helpers
- Used for testing and development
- Simplified database interaction patterns

create_tables.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+"""
+Create database tables.
+"""
+
+import asyncio
+import os
+from dotenv import load_dotenv
+from sqlalchemy.ext.asyncio import create_async_engine
+from src.models.base import Base
+from src.models.investigation import Investigation
+
+load_dotenv()
+
+DATABASE_URL = os.getenv("DATABASE_URL", "sqlite+aiosqlite:///./cidadao_ai.db")
+
+async def create_tables():
+    """Create all tables in the database."""
+    print(f"🔧 Creating tables in: {DATABASE_URL}")
+
+    engine = create_async_engine(DATABASE_URL, echo=True)
+
+    async with engine.begin() as conn:
+        # Create all tables
+        await conn.run_sync(Base.metadata.create_all)
+
+    await engine.dispose()
+    print("\n✅ Tables created successfully!")
+
+if __name__ == "__main__":
+    asyncio.run(create_tables())