Add TLS certificate pinning

[wksantiago]

Summary

• Add TOFU-based TLS certificate pinning for relay connections
• Pin mismatch detection with user-facing warning overlay and clear-and-retry flow
• Certificate pin management UI in settings (view, clear individual, clear all)
• TOCTOU-safe pin verification with selective merge

Test plan

• Connect to a wss:// relay and verify pin is saved on first connection
• Restart and verify reconnection succeeds with pinned certificate
• Simulate certificate change and verify mismatch warning appears
• Clear pin and retry, verify new pin is accepted
• Clear all pins from settings, verify pins file is emptied
• Lock/unlock vault and verify pin mismatch state is cleared

[coderabbitai]

Warning

Rate limit exceeded

@wksantiago has exceeded the limit for the number of commits that can be reviewed per hour. Please wait 23 minutes and 44 seconds before requesting another review.

⌛ How to resolve this issue?

After the wait time has elapsed, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans have higher rate limits than the trial, open-source and free plans. In all cases, we re-allow further reviews after a brief timeout.

Please see our FAQ for further information.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch TLS-certificate

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}