fix(mcp): tighten ingest traces schema for strict clients

[dpersek]

Summary

• Declare supported ingest_traces item fields in the generated MCP schema.
• Set traces.items.additionalProperties to false for strict clients such as Visual Studio Copilot.
• Add a parsed tools/list regression test covering the nested schema path.

Why

Fixes #731.

Visual Studio Copilot rejects codebase_memory_ingest_traces because the nested trace item object schema does not explicitly set additionalProperties: false. The schema now closes that object while still advertising the existing trace payload shape: caller, callee, and optional count.

Tests

• build/c/test-runner mcp - passed, 122 tests.
• git diff --check - passed.
• make -f Makefile.cbm test - built and ran, but failed outside the MCP path with local listener/offline clone environment failures.
• make -f Makefile.cbm lint-ci - blocked locally because cppcheck is not installed.

Scope

• No runtime trace ingestion behavior changes.
• No tool names or handler dispatch changes.
• No manual Visual Studio smoke test was performed.

[DeusData]

Thanks for the strict-client schema fix for #731. Triage: MCP/editor integration compatibility bug.

Review will check the generated tools/list schema shape for strict clients and ensure the actual ingest_traces runtime behavior is unchanged. Nested additionalProperties:false is useful, but it needs to stay aligned with the advertised trace fields.

[DeusData]

Thanks for the precise fix — we verified ingest_traces was the only bare propertyless object schema in the entire TOOLS array, which matches VS complaining exactly there, and your parsed tools/list test is a genuine guard. The declared caller/callee/count fields now become the contract for the future real implementation, which is a nice bonus. Merging — we'll ask the reporter on #731 to verify in VS.