refactor(loop): extract tool-call recovery checks

[zhanghanduo]

Summary

• extract the converged streamed tool-call required-argument recovery check from both products
• expose a typed module-level entry point while keeping schema parsing defensive
• add standalone coverage for malformed schemas, empty/truncated JSON, optional tools, unknown tools, and duplicate failures
• replace the deprecated MiroHarness product name with ApodexHarness in the README

Validation

• uv lock --check
• uv build
• .venv/bin/pytest -q (78 passed)
• .venv/bin/ruff check agent_core tests
• .venv/bin/pyright agent_core (0 errors)