v3.42.10: Code quality fixes

- Remove deprecated io/ioutil
- Fix os.DirEntry.ModTime() usage
- Remove unused fields and variables
- Fix ineffective assignments
- Fix error string formatting

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to dbbackup will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.42.10] - 2026-01-08 "Code Quality"
+
+### Fixed - Code Quality Issues
+- Removed deprecated `io/ioutil` usage (replaced with `os`)
+- Fixed `os.DirEntry.ModTime()` → `file.Info().ModTime()`
+- Removed unused fields and variables
+- Fixed ineffective assignments in TUI code
+- Fixed error strings (no capitalization, no trailing punctuation)
+
 ## [3.42.9] - 2026-01-08 "Diagnose Timeout Fix"
 
 ### Fixed - diagnose.go Timeout Bugs