Add CodeBoarding review and sync workflows

[ivanmilevtues]

Description

Adds CodeBoarding integration workflows for automated code review and context synchronization.

• codeboarding.yml: Triggers on PR open/reopen/ready_for_review and issue comments starting with /codeboarding. Runs CodeBoarding review on the PR.
• codeboarding-sync.yml: Runs on push to main and manual dispatch. Syncs CodeBoarding context via pull request strategy.

Fixes # (issue)

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No

[github-actions]

CodeBoarding review · analyzing…

⏳ CodeBoarding is analyzing this pull request's architecture changes.

_{run 31256291571 · attempt 1}

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 7a304d0405

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Pin the privileged third-party action to a commit

This sync job executes a third-party action from a mutable branch while granting it contents: write, pull-requests: write, and OIDC token access on every push to main; if that branch is moved or the upstream repository is compromised, the replacement code immediately receives those repository privileges. Pin this use—and the matching use in codeboarding.yml—to a reviewed full commit SHA.

Useful? React with 👍 / 👎.