chore: use derive_more::IntoIterator

[LesnyRumcajs]

Summary of changes

Changes introduced in this pull request:

• more derive_more zen

Reference issue to close (if applicable)

Closes

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

Summary by CodeRabbit

• Refactor
  • Enabled derived iterator behavior for a core key type and removed a custom iterator implementation for a collection.
  • Simplified internal iteration mechanics, reducing implementation complexity while preserving existing external behavior and compatibility.

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[coderabbitai]

Walkthrough

TipsetKey now derives IntoIterator via derive_more with an #[into_iterator(owned, ref)] on its inner field; CidHashSet drops its manual IntoIter and IntoIterator impls, relying on the derived iterator behavior.

Changes

Cohort / File(s)	Summary
TipsetKey (derive_intoiterator) src/blocks/tipset.rs	Added derive_more::IntoIterator to TipsetKey and annotated inner field: pub struct TipsetKey(#[into_iterator(owned, ref)] SmallCidNonEmptyVec);. Derive list expanded accordingly.
CidHashSet (remove manual iterator) src/cid_collections/hash_set.rs	Removed manual IntoIter struct and its impl Iterator, and removed the impl IntoIterator for CidHashSet; iteration now uses derived/standard iterator paths.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested reviewers

• akaladarshi
• hanabi1224

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adopting derive_more::IntoIterator to replace manual iterator implementations across the codebase.

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✨ Finishing touches

• 📝 Generate docstrings

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[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@src/cid_collections/hash_set.rs`:
- Around line 13-16: The derived derive_more::IntoIterator on CidHashSet yields
(Cid, ()) tuples from the inner CidHashMap and breaks consumers expecting Item =
Cid; remove the derive for IntoIterator and add custom IntoIterator impls for
CidHashSet and for &CidHashSet: implement IntoIterator for CidHashSet with type
Item = Cid and IntoIter = std::collections::hash_map::IntoKeys<Cid, ()>
returning self.inner.into_keys(), and implement IntoIterator for &'a CidHashSet
with type Item = &'a Cid and IntoIter = std::collections::hash_map::Keys<'a,
Cid, ()> returning self.inner.keys() so iteration yields keys only.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.69%. Comparing base (31b5936) to head (8773c2c).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

Files with missing lines	Coverage Δ
src/blocks/tipset.rs	87.97% <ø> (+0.50%)	⬆️
src/cid_collections/hash_set.rs	23.07% <ø> (+6.86%)	⬆️

... and 8 files with indirect coverage changes

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