fix: improve FilePersistenceService code quality and security

wanshenmean

2026-03-13 efbfb630f60f6663deba83ec12c1fbf2f9bab183

 .gitignore

@@ -1,8 +1,12 @@
# Build and Object Folders  
bin/  
obj/  
  
# Nuget packages directory  
# Build and Object Folders
bin/
obj/

# Git worktrees (isolated workspaces)
.worktrees/
worktrees/

# Nuget packages directory
packages/  
  
## Ignore Visual Studio temporary files, build results, and