v0.7.1: Tool-schema token budget

Tool-schema token budget

Every connected MCP client loads the full tools/list payload into model context at every session start. This release trims the schema descriptions from ~2800 to ~2370 estimated tokens (record_decision alone was 738) and adds a regression test capping the payload at 2500 -- future fields must fit the budget or consciously raise it.

Nothing behavioral changed: rich field guidance still reaches the model where it is lazy-loaded (validation rejection messages via _FIELD_GUIDANCE, and CLAUDE.md), so capture quality enforcement is unchanged. 121 tests passing; held-out retrieval eval unchanged (hit@5 80%, MRR 0.700).