chore(rng): post-convergence housekeeping

[EffortlessSteven]

Summary

• Update root Cargo.toml RNG comments to reflect the current convergence state: the workspace-wide RNG line now covers all crates except the rsa/pgp/x509 blocked islands, and the RSA section comments document the specific blocker (rsa 0.9 on rand_core 0.6).
• Annotate Dependabot ignore rules in .github/dependabot.yml with context explaining why major-bump PRs for rand, rand_core, and rand_chacha are suppressed (upstream blockers in rsa 0.9 and pgp 0.19).
• Add ed25519-dalek to the crypto dep guard in dep_guard_policy.rs so duplicate major versions of that crate are caught by the guard test.

Test plan

• cargo xtask test passes (dep guard test exercises the new ed25519-dalek entry)
• Verify Cargo.toml and dependabot.yml comments read correctly

[gemini-code-assist]

Warning

You have reached your daily quota limit. Please wait up to 24 hours and I will start processing your requests again!

[coderabbitai]

Warning

Rate limit exceeded

@EffortlessSteven has exceeded the limit for the number of commits that can be reviewed per hour. Please wait 4 minutes and 48 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.

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 8443f7e3-53cc-48b3-8020-13b4ac7a3ae2

📥 Commits

Reviewing files that changed from the base of the PR and between dec803c and c4c2b36.

📒 Files selected for processing (3)

• .github/dependabot.yml
• Cargo.toml
• crates/uselesskey/tests/dep_guard_policy.rs

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch chore/rng-convergence-housekeeping

📝 Coding Plan

• Generate coding plan for human review comments

---

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.}