fix: accept SQLAlchemy-style connection URLs with driver hints

[datlechin]

Summary

• Strip driver hint suffixes (e.g., +psycopg, +asyncpg, +pymysql) from connection URL schemes before matching database type
• postgresql+psycopg://... now parses as PostgreSQL, mysql+pymysql://... as MySQL, etc.
• Preserves +ssh (SSH tunneling) and +srv (MongoDB SRV) behavior

Closes #642

Test plan

• Paste postgresql+psycopg://user:pass@localhost:5432/mydb → parses as PostgreSQL
• Paste postgresql+asyncpg://user:pass@localhost:5432/mydb → parses as PostgreSQL
• Paste mysql+pymysql://user:pass@localhost:3306/mydb → parses as MySQL
• Paste mongodb+srv://user:pass@cluster.example.com/mydb → still parses as MongoDB (not stripped)
• Paste postgresql+ssh://user:pass@localhost/mydb → still enables SSH mode
• Existing URLs without driver hints continue to work unchanged