chore: Prepare 18.13.5

[BinaryMuse]

No description provided.

[greptile-apps]

Greptile Summary

Version bump from 18.13.5 across all workspace crates, with corresponding CHANGELOG entry noting the Atuin Hex init fix (#3341) and a docs fix (#3338). No logic changes — purely a release preparation commit.

Important Files Changed

Filename	Overview
CHANGELOG.md	Adds 18.13.5 release notes with bug fix and docs entries.
Cargo.toml	Workspace version and all workspace dependency versions bumped to 18.13.5.
Cargo.lock	All atuin crate versions updated to 18.13.5 in the lockfile.

_{Reviews (1): Last reviewed commit: "Update changelog" | Re-trigger Greptile}