Implement marker-based portable storage, portable WebView and log paths, secure queue and migration sanitization, and Windows portable ZIP validation while preserving the NSIS installer path. Refs #15
Set the NSIS installer and uninstaller icon to the existing Firelink .ico asset so Windows setup files do not fall back to the default NSIS icon.
Add target-aware engine provisioning, platform package configs, and CI/release verification for macOS arm64, Windows x64, and Linux AppImage.