fix blocking during long queries

[joe-clickhouse]

Summary

• Keep the public query helpers sync while making MCP query execution non-blocking
• Queries were already dispatched to a thread pool, but the MCP tool path still blocked the event loop while waiting for results. This change adds async MCP-facing wrappers for ClickHouse and chDB queries that await thread-pool futures with asyncio.wait_for() while preserving the existing synchronous run_query and run_chdb_select_query APIs for direct Python callers
• Other MCP requests, including list_tools can now be served while a query is in flight

Closes #128

[Copilot]

Pull request overview

This PR addresses MCP server responsiveness issues during long-running ClickHouse/chDB queries by making the query tools non-blocking with respect to the asyncio event loop, so other MCP requests can be served while a query is in-flight (closes #128).

Changes:

• Converted run_query and run_chdb_select_query to async def and replaced blocking future.result() with asyncio.wrap_future() + await asyncio.wait_for(...).
• Updated synchronous unit tests to call the now-async functions via small asyncio.run(...) helpers.
• Added required asyncio imports where needed.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
mcp_clickhouse/mcp_server.py	Makes ClickHouse/chDB query tools await threadpool futures instead of blocking the event loop thread.
tests/test_tool.py	Adjusts tests to invoke async run_query from sync unittest methods.
tests/test_chdb_tool.py	Adjusts tests to invoke async run_chdb_select_query from sync unittest methods.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

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