Keep Sharesight's portfolio list and single-day reports warm

[robdevops]

Summary

A keep_warm option on MCP servers refetches cached results in the background just before the 30-minute cache_ttl expires, so asking about a portfolio never waits on a cold fetch. Sharesight is configured with {"list_portfolios": null, "get_performance_report": 0}: the portfolio list always, and get_performance_report only for a single-day window (start_date equal to end_date).

Behaviour

• An entry is refetched about 30 seconds before it expires, but only if someone asked for it since it was last fetched. A query nobody repeats is dropped at the next expiry, so it stops costing API calls.
• A refetch that fails or returns an error drops the entry, and the next real request fetches it again.
• Calls outside the window rule (longer windows, undated reports) are still cached for the full TTL, just never refreshed. That includes the daily holding-news check, which asks for a portfolio with no dates.
• keep_warm takes a list of tool names or {tool: longest start_date..end_date window in days, 0 = a single day}. A name that matches no tool is warned about, like blocked_tools.

Files

• lib/mcp/server.py: cache entries carry their tool and arguments; a background loop runs while the server is connected. The module is now 325 lines, a little over the ~300 guideline.
• mcp_servers.json, README.md: config and documentation.
• tests/test_mcp.py: refresh before expiry and serving the refreshed copy, idle entries dropped, window rule for days 0 and 1, failed refresh, unknown name warning, shipped config pinned.

Test plan

• make check on Python 3.13.5 (ruff + pytest): 220 passed
• CI check job on this PR
• Live Sharesight behaviour is not exercised (no network in tests)

🤖 Generated with Claude Code

https://claude.ai/code/session_014k4kywyN5dAo39izUPvxbw

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