feat: add Wine Z: path prefix for Windows platform on Linux host

- Add winePath helper that prepends Z: when platform is windows on Linux
- Thread platform through buildModPath, buildAutoArgs, and Start()
- Apply Z: prefix to -config=, -mod=, -profiles=, and %command% binary paths
- Add tests for winePath, buildAutoArgs, and buildModPath with platform param
- Fix formatting across services package with gofmt
- Include all prior bug fixes from this branch

backend/internal/services/config_manager.go

@@ -16,8 +16,8 @@ func NewConfigManager(cfgDir string) *ConfigManager {
 }
 
 type ConfigInfo struct {
-	Name    string `json:"name"`
-	Size    int64  `json:"size"`
+	Name string `json:"name"`
+	Size int64  `json:"size"`
 }
 
 func (cm *ConfigManager) List() ([]ConfigInfo, error) {