docs: add eval_test suite to tests README (#354)

* chore: remove temporary seed and DDL extraction files

These files (seed_tdml_summaries.py and extracted DDL scripts) were created
during development for testing database connectivity and seeding teradataml
summaries. They are no longer needed and should not be version-controlled.

* chore: upgrade langsmith to >=0.8.18

Add explicit langsmith dependency with minimum version 0.8.18.
Updates lock file to 0.9.1, the latest compatible version.

* chore: upgrade pydantic-settings to >=2.14.2

Add explicit pydantic-settings dependency with minimum version 2.14.2.
Updates lock file to 2.14.2.

* Improve error reporting in evals: unwrap ExceptionGroup to show actual error

* Fix asyncio.run() conflict in pytest context: use ThreadPoolExecutor when event loop already running

* chore: clean up eval results and update gitignore

- Remove eval test results directory (large transient files)
- Add results/, .mypy_cache/, .deepeval/, and .pytest_cache/ to gitignore
- These are build artifacts and should not be tracked

* docs: add eval_test suite to tests README

Author: dtehan-td

tests/README.md

@@ -1,4 +1,5 @@
 # Tests
 
 - [Integration test suite](integration/README.md) — MCP tool tests, case definitions, and setup scripts
+- [Evaluation suite](eval_test/README.md) — LLM agent tool selection and parameter formation tests using deepeval
 - [Performance benchmarks](mcp_bench/README.md) — load and concurrency testing