Remove Daft ClickHouse dependency and binding

[jiangxt2]

Description

Remove Tributo's built-in Daft ClickHouse Binding and daft-clickhouse from the clickhouse extra and runtime-image contracts. Keep clickhouse-connect and the existing Ray ClickHouse Binding with its external ray-clickhouse==0.1.0 wheel path. Update the lock file, route tests, runtime-image checks, API reference, and support documentation. Make the binding-test metadata mock fall back to real lookups for distributions outside its fixture map so the isolated Ray diagnostic test is order-independent.

Selecting Daft for ClickHouse no longer resolves a built-in route; Ray-based ClickHouse reads remain available.

Related issues

None.

Additional information

• Tests: uv run --locked --no-sync python scripts/pr-precheck.py passed with two non-blocking warnings; the CI unit suite passed on Python 3.12 and 3.13, and documentation checks passed. The focused Iceberg diagnostic test passed both engine parametrizations.
• Static checks passed: uv lock --check --offline, python3 tools/generate_public_api_reference.py --check, JSON parsing for tests/integrations/runtime-profiles.json, Ruff lint/import/format checks, and git diff --check.
• The precheck warnings are the pre-existing inline import at tests/data/test_source_bindings.py:847 and the repository's large uv.lock file.
• No new runtime dependencies were added; clickhouse-connect remains in the clickhouse extra.
• Real ClickHouse conformance remains an external validation gate.