[Jmmt-mingrui]

Summary

• request get_query_guide only once before the first data query in each conversation context
• reuse the returned guide across follow-up queries, database changes, workspace changes, and routing changes
• request it again only after a new or reset context
• avoid unsafe server-side session caching when one MCP connection serves multiple conversations
• update server instructions, tool metadata, docs, and regression tests

Validation

• 253 unit tests passed
• offline test suite passed
• Python compile check passed