Migrate note storage from Registry to file system

[zzy-life]

Summary

This PR migrates the Desktop Notes application from storing note data in the Windows Registry to a file-based storage system in the AppData directory, while maintaining backward compatibility with existing user data.

Key Changes

REGISTRY.cs

• Storage Migration: Moved note data storage from HKEY_CURRENT_USER\Software\Sand Soft\Desktop Notes to %AppData%\Desktop_Notes\notes\
• Data Directory Structure:
  • %AppData%\Desktop_Notes\ - Main data directory
  • %AppData%\Desktop_Notes\notes\ - Individual note files (JSON format)
  • %AppData%\Desktop_Notes\_DefaultSettings.json - Default note settings
• Backward Compatibility: Added MigrateFromRegistry() method that automatically detects and migrates existing Registry data to the new file-based storage on first run
• Registry Cleanup: After successful migration, old Registry entries are deleted and empty Registry keys are removed
• Default Settings: Moved SaveDefaultSettings() and GetDefaultSettings() from Registry to file-based storage
• System Settings: Kept Windows startup settings in Registry (unchanged)

MainForm.cs

• Loading State Management: Added _isLoading flag to prevent saving during form initialization
• Property Access: Changed direct property assignments to use backing fields (_theme, _style) with proper validation
• Save Guard: Modified Save() method to skip saving while form is loading to prevent data corruption
• Error Handling: Wrapped LoadData() in try-finally block to ensure _isLoading flag is properly reset

Product.wxs

• Installer Upgrade Sequence: Changed MajorUpgrade schedule from afterInstallExecute to afterInstallInitialize for more reliable upgrades
• Application Launch: Adjusted custom action timing for running the main executable

Implementation Details

• All note data is now stored as individual JSON files with pretty-printing for readability
• Migration is automatic and transparent to users - existing Registry data is detected and migrated on first run
• File-based storage provides better scalability and easier backup/portability compared to Registry
• The migration process includes error handling to ensure data integrity even if individual entries fail to migrate

https://claude.ai/code/session_01C8uHLbTTSPExtKZ7pNi56j