refactor(plugin): preserve Windows filenames in native helpers

[kmbroai]

Summary

Preserve Windows filenames when replacing Python path handling with TypeScript. Node can replace lone UTF-16 surrogates in arguments, environment variables, and directory names, so helpers need the original Windows values.

Stacked on #797.

Changes

• Add native access to original arguments, environment values, absolute paths, and directory entries as UTF-16LE buffers.
• Preserve cached directory attributes and symbolic-link tags so inventory can distinguish directory symlinks from junctions without opening unrelated files.
• Add a typed filesystem adapter using the existing Windows handles, including canonical paths, metadata, bounded reads, output writes, and recursive directory creation. Path normalization follows CPython's Windows behavior, including UNC/device prefixes and drive-relative paths.
• Exercise surrogate and replacement-character filenames, verbatim and long paths, inaccessible unrelated files, directory links, and process values through a Rust-launched Windows proof. The test executable is excluded from uploaded runtime artifacts.

Testing

• On the rebased head: TypeScript compilation, SDK/MCP types, formatting, Rust formatting, Ruff, portable source checks, and all nine checker tests passed.
• A fresh Linux native build and behavioral proof passed. The Windows implementation is unchanged by the rebase; earlier 5,545 C-normalizer comparisons per Node version are recorded in the PR history.
• Actual Windows x64/arm64 execution remains a hosted CI gate.

Risk and rollout

This prepares the following helper migration. It adds native operations without changing existing command routing or public CLI syntax. Windows CI must validate the updated native library and process proofs before merge.

Public disclosure review

• No customer, partner, prospect, or user identities, data, or identifying details are included.
• No credentials, personal data, private source, scan findings, or nonpublic links or tickets are included.
• I reviewed the branch name, title, description, commits, changes, comments, logs, screenshots, attachments, and links for public disclosure.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
🔒 Security Review	✅ Completed 2026-09-03T19:21:11.374559Z	0f1995a	New commits

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