release: bump Codex Security to 0.1.8

[kmbroai]

Summary

• Bump @openai/codex-security from 0.1.7 to 0.1.8 with a one-line change on the latest main.
• Release the fixes already merged since npm-v0.1.7 while keeping the frozen dependency lockfile and protected release workflows unchanged.

Validation

• Confirmed public main and npm latest are both 0.1.7.
• Confirmed there is no open competing Codex Security release PR, no matching release branch, and no npm-v0.1.8 tag.
• Not run locally: this is a version-only change created directly against the OSS repository; normal PR CI will validate it.

Release

After review and merge, the existing node-release-cut workflow observes the higher version on main, creates npm-v0.1.8 on the exact merged commit, and dispatches the protected, provenance-enabled node-release workflow.

Opening or merging this PR does not itself publish the package; publication still requires the protected npm deployment approval.