Summary

Adds a non-Anthropic compatibility layer for tool calls by introducing:

• src/agents/tool-call-validator.ts
• src/agents/tool-call-repair.ts

These are wired to normalize and recover malformed tool-call payloads seen in non-Anthropic providers.

What quirks this handles

• MiniMax M2.5: provider responses that emit incomplete or schema-divergent tool-call objects.
• GLM-5: argument formatting and shape inconsistencies in tool-call payloads.
• Grok 4: tool-call envelope/field irregularities that break strict downstream parsing.

Why this PR

This work is already implemented and committed on roman/tool-reliability; this PR is for review/merge into the active megabranch.

Verification

• Run Monday discovery verification before merge.
• Confirm tool-call execution succeeds across MiniMax M2.5, GLM-5, and Grok 4 on representative scenarios.

Notes

• Scope is limited to the compatibility validation + repair layer (no unrelated code changes).