rsky-repo cargo clippy

[seanwatters]

Summary

some basic cleanup with cargo clippy. silences warnings for dead_code and some deprecated -- adding todo comments to resolve later.

this could be a precursor to going full clippy::pedantic which would probably be beneficial if the community decides that generating code with LLMs is valid for this project.

a lot of these fixes have minor impacts on performance or get us closer to more idiomatic Rust usage, but clippy::pedantic can help with even more aggressive perf optimization lints (discouraging needless .clone() or passing by value where a reference will do).

it might also be worth adding cargo clippy command as a quality gate for PR approval after all the warnings have been addressed.

EDIT: also as a tip for maintainers -- depending on your editor or IDE you can set on-the-fly syntax checking to cargo clippy instead of cargo check so that you can see the hints inline

blocked by #179

Related Issues

#181

Changes

• Feature implementation
• Bug fix
• Documentation update
• Other (please specify): perf/lints

Checklist

• I have tested the changes (including writing unit tests).
• I confirm that my implementation aligns with the canonical Typescript implementation and/or atproto spec
• I have updated relevant documentation.
• I have formatted my code correctly
• I have provided examples for how this code works or will be used