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/api/health.go

@@ -76,7 +76,7 @@ func (h *Handler) Health(c *gin.Context) {
 			Running: h.steamcmd.IsRunning(),
 		},
 		Frontend: FrontendHealth{
-			Served: true,
+			Served: h.frontendServed,
 		},
 	}
 
@@ -140,8 +140,6 @@ func findServerBinary(serverfileDir string) (string, bool) {
 	candidates := []string{"arma3server_x64"}
 	if runtime.GOOS == "windows" {
 		candidates = append(candidates, "arma3server_x64.exe")
-	} else {
-		candidates = append(candidates, "arma3server_x64.exe")
 	}
 	for _, name := range candidates {
 		p := filepath.Join(serverfileDir, name)