Add single-instance enforcement and DirectWrite crash workaround

- Implement mutex-based single instance check
- Show message if app is already running
- Force software rendering to prevent DirectWrite font initialization crash
- Update version to 1.0.2

Fixes:
- Multiple instances could run simultaneously
- DirectWrite crash on certain Windows configurations

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Installer/Product.wxs

@@ -3,7 +3,7 @@
   <Product Id="*"
            Name="NFC Actions"
            Language="1033"
-           Version="1.0.0.0"
+           Version="1.0.2.0"
            Manufacturer="Dangerous Things"
            UpgradeCode="A1B2C3D4-E5F6-4A5B-8C9D-0E1F2A3B4C5D">