GeezerVison

Summary

Keep CSV reader state in a shared native parser while releasing short payload borrows before callbacks, reference drops and Python allocation. Includes the first consumer of the interpreter-bound PyOperation facade, the existing float-error helper extraction, and the whole canonical CSV free-threading test file.

This is a functionality-based extraction from #9439, based on main 84d7afc2d59e05c66c92df3ce0854679d2b32b52. The original aggregate is being narrowed to monitoring. The extracted files are preserved exactly from the reviewed aggregate source.

All included Lib files were regenerated with actual scripts/update_lib migrate from CPython d220409a13b77de7a6c30abe16ea90db01528edc and match that pin byte-for-byte. No test file is split across PRs and no assertions or skips are added.

Validation and limits

Earlier aggregate: 24 serial CSV oracles and 11 ordinary canonical methods passed on a different combined executable. They are historical evidence only; fresh standalone hosted CI is still required. No new local concurrency test was run.

Fresh standalone check and strict Clippy (-D warnings) passed for both rustpython-stdlib --lib --no-default-features --features compiler,threading,host_env,doc,ucd_3_2_0 and rustpython-vm --lib --no-default-features --features compiler,threading,host_env,stdio,doc,importlib on the 84d7 base. Dependencies were locked/offline; source hashes were verified before and after. The newly landed float-power implementation is preserved alongside the extracted float-error helper. No runtime test was run for this extraction. Exact-head hosted CI: pending. Old aggregate green checks are historical, not standalone validation of this extraction.