This commit addresses several code quality issues identified in the
recent bash 3.2 compatibility fixes:
1. Remove redundant array length check in is_whitelisted()
- The second check for array length > 0 is unnecessary after
already checking for length == 0
2. Clean up commented dangerous cleanup code in dev.sh
- Replace commented-out code with clear documentation
- Add explicit notes explaining why certain paths are excluded
- Improves maintainability by preventing confusion
3. Enhance test coverage for excluded paths
- Add tests to verify Mix archives are NOT cleaned
- Add tests to verify Stack programs are NOT cleaned
- Add tests to verify VS Code workspace storage is NOT cleaned
- These tests ensure critical data remains protected
All changes pass ShellCheck, syntax validation, and formatting checks.
