PR checklist

Verbatim from AGENTS.md and CONTRIBUTING.md. Run through this list before pushing. The order matters: the gate checks come before the code checks because failing a gate check means the PR will be closed without anyone running your tests.

1. Gate

• A GitHub issue exists describing the change.
• A librustzcash team member has acknowledged the issue.
• The PR description links the issue (Fixes #N or Closes #N for issue-closing PRs).

2. Scope

• One concern per PR. Refactors, formatting fixes, and code changes go in separate PRs.
• One crate per PR when possible. Cross-crate changes need a stronger justification in the PR description.

3. Local build and test

• cargo build --workspace --all-features passes.
• cargo test --workspace --all-features passes.
• cargo fmt --all -- --check passes.
• cargo clippy --workspace --all-features --all-targets -- -D warnings passes.

4. Changelog

• User-facing changes have an entry in the affected crate's CHANGELOG.md.
• The changelog entry is in its own commit, separate from the code change.
• The entry follows the conventions of recent merged entries (check git log --oneline -- <crate>/CHANGELOG.md).

5. Dependencies (only if you touched Cargo.toml)

• cargo vet passes locally. Update supply-chain/audits.toml or supply-chain/imports.lock as required.
• New dependencies are justified in the PR description.
• No dependency downgrade unless explicitly motivated.

6. Commit hygiene

• Commit titles are under 80 characters.
• Each commit builds and tests pass at that commit (bisect safety).
• No "WIP", "fixup", or "squash" commits.
• If the repo requires DCO sign-off, every commit has it (git commit -s).

7. Documentation

• Public APIs have rustdoc comments.
• Breaking changes are flagged in both the changelog entry and the PR description.

8. Re-read before pushing

• AGENTS.md "MUST READ FIRST" section.
• The diff once more, slowly. Reviewers' time is the bottleneck; a self-review pass catches most surface issues.