refactor(plugin): port security policy resolution to TypeScript

[kmbroai]

Summary

Replace the Python SECURITY.md resolver and its tests with a typed helper bundled alongside the MCP runtime. Policy discovery and root-to-leaf guidance use the existing Node launcher.

Changes

• Preserve containment, symlink and junction behavior, byte limits, UTF-8 handling, home expansion, inventory ordering, accepted arguments, and output formats.
• Preserve POSIX path bytes and Windows UTF-16 process values and paths; compare canonical Windows components without losing characters during case conversion.
• Invoke launch_codex_security_mcp[.cmd] --helper resolve-security-md --repo PATH [--list | --scope PATH] [--out PATH], defaulting to stdout. Limit the SDK's Python interpreter instruction to .py helper scripts.
• Document intentional compatibility for abbreviated options, inherited help behavior, named-user expansion, and home-variable precedence. Replace complete Markdown snapshots with semantic source/content/order assertions and dedicated framing checks.
• Retain the compatible path resolver after native realpath comparisons showed different existing-file parent behavior. Remove the completed characterization probe and describe the active TypeScript policy helper in the native documentation.

Testing

• After the Windows File integration: both MSVC-target Clippy checks, CI-tool compilation, proof syntax, Rust/TypeScript formatting, workflow lint, Ruff, portable source checks, and all nine checker tests passed.
• 34 policy/launcher tests passed locally, with four Windows-only skips, plus the focused SDK prompt test.
• After correcting malformed short-help errors, 32 helper tests passed with three Windows-only skips and 180 assertions. All 19 help-suffix comparisons matched the deleted Python helper.
• SDK/MCP TypeScript checks, formatting, Ruff, portable source checks and all nine checker tests passed.
• Completed comparisons on GNU Linux, musl, and macOS established the native file-parent behavior. The deleted Python helper independently confirmed the retained compatibility behavior.
• Hosted CI exercises macOS, glibc, musl, and Windows fixtures on both architectures. Resolver tests retain file-parent, missing-path, symlink-cycle, and raw-byte behavior.

Risk and rollout

Stacked on #798. The helper entrypoint changes from the Python script to the shared launcher, with callers updated together. Previously accepted arguments and home expansion remain supported intentionally. GNU Linux file/.. compatibility requires retaining the existing resolver; native realpath is not a drop-in replacement. Other Python helpers remain for subsequent migration slices. There are no new top-level CLI flags.

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 2026-09-05T01:46:17.346644Z	9986e31	New commits

Security findings

Blocking findings (1)

• 🔴 Resolve helper Node outside the scanned repository · High · Dismissed · From earlier review · ad511ed

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[chatgpt-codex-connector]

💡 Codex Security Review

Here are some automated security review suggestions for this pull request.

Reviewed commit: ad511edcbb

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[mldangelo-oai]

Re-reviewed the exact current head and reconciled all prior threads. The compatibility behavior is well covered; the remaining comments are nonblocking simplification and documentation cleanup.

[mldangelo-oai]

[P3] Keep migration archaeology out of operator guidance

Thanks for making the compatibility choice explicit. These three paragraphs now spend 274 words on parser error ordering, pathological home-variable states, and a GNU realpath discrepancy—details an agent invoking the helper cannot act on. Could we replace them with the actionable contract, for example:

For compatibility, the resolver retains the former Python helper's option abbreviations, help parsing, home expansion, and path resolution; prefer the full option names shown above.

Quote tilde paths so the helper expands them for --repo and --scope; --out keeps tildes literal, and --out - writes to stdout.

That preserves the supported surface while cutting about 227 words and avoids turning implementation quirks into durable product guidance.