fix: eliminate TOCTOU race conditions in ssl-bump.ts

[Mossaka]

Tracking issue from closed PR #766.

Replace check-then-act pattern (existsSync + writeFileSync) with atomic file creation using the wx flag (O_WRONLY | O_CREAT | O_EXCL) in initSslDb().

Changes needed

• Replace existsSync + writeFileSync with atomic wx flag writes
• Handle EEXIST errors gracefully (file already exists is not an error)
• Eliminate TOCTOU (time-of-check-time-of-use) race conditions

Original PR: #766

[github-actions]

👋 Hello! I noticed this issue is closely related to:

• test: add comprehensive coverage for TOCTOU fix error paths #837 - "test: add comprehensive coverage for TOCTOU fix error paths"

Both issues track work from the same PR chain (#766 and #768) and address the TOCTOU fix in ssl-bump.ts. However, they have complementary focuses:

• This issue (fix: eliminate TOCTOU race conditions in ssl-bump.ts #838): Implements the TOCTOU fix code changes
• Issue test: add comprehensive coverage for TOCTOU fix error paths #837: Adds test coverage for the TOCTOU fix error handling

These are separate tracking issues for different aspects of the same feature and should both remain open.

This is an automated message from the issue duplication detector.

AI generated by Issue Duplication Detector

[github-actions]

🍪 Issue Monster has assigned this to Copilot!

I've identified this issue as a good candidate for automated resolution and assigned it to the Copilot agent.

The Copilot agent will analyze the issue and create a pull request with the fix.

Om nom nom! 🍪

AI generated by Issue Monster