fix(security-guidance): use a cross-platform Python launcher

[Rohan5commit]

Summary

• use a small Node launcher so the security-guidance hook can find Python on Windows and Unix-like systems
• preserve stdin/stdout passthrough for the existing Python reminder hook
• add focused tests for launcher selection and fallback behavior

Testing

• node --test plugins/security-guidance/hooks/run_python_hook.test.js

Closes #46449

[Copilot]

Pull request overview

This PR fixes the security-guidance plugin’s Python hook invocation so it works on Windows (where python3 may not exist) by introducing a small Node-based launcher that tries multiple Python entrypoints and preserves hook I/O behavior.

Changes:

• Add a Node launcher (run_python_hook.js) that attempts platform-appropriate Python commands and falls back when commands are missing.
• Update hooks.json to invoke the Node launcher instead of calling python3 directly.
• Add Node tests covering launcher selection and ENOENT fallback behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
plugins/security-guidance/hooks/run_python_hook.js	New Node launcher that selects/falls back between Python launchers and proxies stdin/stdout/stderr.
plugins/security-guidance/hooks/run_python_hook.test.js	Tests for launcher ordering and fallback behavior when the first launcher is missing.
plugins/security-guidance/hooks/hooks.json	Switch hook command to use the Node launcher with the existing Python hook script.

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[Copilot]

spawnSync returns status: null when the child is terminated by a signal (with signal set). The current return expression treats that case as success (0) when result.error is falsy, which can silently mask real failures. Consider returning a non-zero exit code when status is null due to result.signal (or generally defaulting null status to 1 unless the error is ENOENT and you intend to fall through).

Suggested change

	return result.status ?? (result.error ? 1 : 0);
	return result.status ?? 1;