fix(file-ops): use sort_by_key to satisfy clippy 1.95 lint

[lobinuxsoft]

Summary

Unbreaks CI after GitHub runners updated to Rust 1.95 stable, which introduced the unnecessary_sort_by clippy lint.

The problem

crates/file-ops/src/browse.rs:59 was using sort_by with a case-insensitive comparator. Rust 1.95's new clippy flags this as replaceable with the lighter sort_by_key. Since CI enforces -D warnings, every PR against development breaks once the runner pulls 1.95.

Hit while trying to merge #237 — Rust Lint was the only failing check, even though that PR was a one-line submodule pointer bump.

The fix

- result.sort_by(|a, b| a.name.to_lowercase().cmp(&b.name.to_lowercase()));
+ result.sort_by_key(|entry| entry.name.to_lowercase());

Mechanical substitution suggested by clippy itself. Semantically identical: both sort case-insensitively by entry.name.

Test plan

• cargo check -p capydeploy-file-ops passes locally
• CI green on Rust 1.95 (will validate once workflows run)
• feat(decky): bump plugin to v1.1.0 with persistent progress visibility #237 can be rebased and will no longer be blocked by this check