feat: Add SAP HANA data source connector

[fdu-songyazhou]

Is your feature request related to a problem?

There is currently no support for SAP HANA as a data source in WrenAI.

Describe the solution you'd like

Add SAP HANA as a supported data source, allowing users to connect their SAP HANA databases for semantic modeling and AI-powered natural language querying.

SAP HANA is widely adopted in enterprise environments as a high-performance in-memory database for both OLTP and OLAP workloads. Supporting it would open WrenAI to a large enterprise user base.

Connection properties

• Host
• Port (default: 30015)
• Username / Password
• Database name (optional, for multi-tenant setups)
• Schema (optional)
• TLS encryption toggle

Additional context

• SAP provides an official Python driver hdbcli (available on PyPI)
• Similar in scope to the existing Oracle connector

[Pawansingh3889]

I'd like to take this on. I've scoped it against the existing Oracle connector and it looks like the touchpoints are:

• core/wren/src/wren/connector/hana.py (new) — native hdbcli connector with a HANA→Arrow type map, mirroring oracle.py
• connector/factory.py — register DataSource.hana
• model/data_source.py — hana enum + HanaConnectionInfo + match case
• model/__init__.py / field_registry.py — export the new ConnectionInfo
• wren-mdl/mdl.schema.json — schema entry
• wren-ui data-source form

Two questions before I start so I build it the way you'd want:

1. Scope — should this PR cover the wren-ui connection form as well, or is a separate UI PR preferred (keeping the ibis-server/connector change reviewable on its own)?
2. Testing — Oracle's connector has live-DB-shaped tests. I don't have a SAP HANA instance handy; is the SAP hanaexpress Docker image the expected way to test locally, or do you mock the driver in the connector tests?

Happy to open a draft early once I've got the connector + type map roughed in.