feat: install WinUSB driver via KneronPLUS SDK (libwdi)

The KneronPLUS wheel bundles libwdi.dll and provides
kp.core.install_driver_for_windows() which handles WinUSB driver
installation internally. This replaces the unreliable pnputil +
self-signed INF approach that failed due to unsigned INF rejection.

Changes:
- Split USB setup into two steps: "Setting up USB library" (extract
  libusb DLL + driver files) and "Installing USB device driver"
  (runs after Python/kp are installed)
- New installKneronDriverViaSDK() calls kp SDK to install WinUSB
  for KL520, KL720, and KL720_LEGACY product IDs
- Driver files still extracted as manual Zadig fallback
- macOS/Linux: installUSBDriver() is a no-op

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

edge-ai-platform/installer/app.go

@@ -230,8 +230,9 @@ func (inst *Installer) runInstall(config InstallConfig) {
 		{"Extracting models and firmware", 30, true, inst.stepExtractData},
 		{"Extracting scripts", 48, true, inst.stepExtractScripts},
 		{"Configuring system", 55, false, inst.stepConfigureSystem},
-		{"Setting up USB driver", 62, false, inst.stepSetupLibusb},
+		{"Setting up USB library", 62, false, inst.stepSetupLibusb},
 		{"Setting up Python environment", 70, false, inst.stepSetupPython},
+		{"Installing USB device driver", 76, false, inst.stepInstallUSBDriver},
 		{"Installing media tools", 78, false, inst.stepInstallFfmpeg},
 		{"Writing configuration", 85, true, inst.stepWriteConfig},
 		{"Verifying installation", 90, false, inst.stepVerify},
@@ -325,6 +326,10 @@ func (inst *Installer) stepSetupPython(config InstallConfig) error {
 	return inst.setupPythonVenv(config.InstallDir)
 }
 
+func (inst *Installer) stepInstallUSBDriver(config InstallConfig) error {
+	return installUSBDriver(config.InstallDir)
+}
+
 func (inst *Installer) stepVerify(config InstallConfig) error {
 	binName := "edge-ai-server"
 	if runtime.GOOS == "windows" {

edge-ai-platform/installer/platform_darwin.go

@@ -102,6 +102,11 @@ func checkLibusbInstalled() bool {
 	return exec.Command("brew", "list", "libusb").Run() == nil
 }
 
+// installUSBDriver is a no-op on macOS (libusb handles USB access).
+func installUSBDriver(installDir string) error {
+	return nil
+}
+
 func removeQuarantine(installDir string) {
 	binPath := filepath.Join(installDir, "edge-ai-server")
 	exec.Command("xattr", "-dr", "com.apple.quarantine", binPath).Run()

edge-ai-platform/installer/platform_linux.go

@@ -92,6 +92,11 @@ func checkLibusbInstalled() bool {
 	return exec.Command("dpkg", "-s", "libusb-1.0-0-dev").Run() == nil
 }
 
+// installUSBDriver is a no-op on Linux (udev rules handle USB access).
+func installUSBDriver(installDir string) error {
+	return nil
+}
+
 func removeQuarantine(installDir string) {
 	// No-op on Linux
 }

edge-ai-platform/installer/platform_windows.go

@@ -129,9 +129,86 @@ func installLibusb(installDir string) error {
 		}
 	}
 
-	// 2. Extract and install WinUSB driver for Kneron devices
-	if err := installWinUSBDriver(installDir); err != nil {
-		return err
+	// 2. Extract WinUSB driver files (for manual fallback)
+	extractWinUSBDriverFiles(installDir)
+
+	// 3. Install WinUSB driver via KneronPLUS SDK (uses libwdi internally)
+	// This is called after Python venv + kp wheel are installed (step 7),
+	// so we defer the actual driver install to postInstallDriver().
+	// Here we just extract the files.
+
+	return nil
+}
+
+// extractWinUSBDriverFiles extracts INF and co-installer DLLs from payload
+// for manual fallback (Zadig). The actual driver install happens via kp SDK.
+func extractWinUSBDriverFiles(installDir string) {
+	driverDir := filepath.Join(installDir, "drivers")
+	os.MkdirAll(filepath.Join(driverDir, "amd64"), 0755)
+
+	driverFiles := map[string]string{
+		"payload/drivers/kneron_winusb.inf":             filepath.Join(driverDir, "kneron_winusb.inf"),
+		"payload/drivers/amd64/WdfCoInstaller01011.dll": filepath.Join(driverDir, "amd64", "WdfCoInstaller01011.dll"),
+		"payload/drivers/amd64/winusbcoinstaller2.dll":  filepath.Join(driverDir, "amd64", "winusbcoinstaller2.dll"),
+	}
+
+	for src, dst := range driverFiles {
+		data, err := payloadFS.ReadFile(src)
+		if err != nil {
+			continue
+		}
+		os.WriteFile(dst, data, 0644)
+	}
+}
+
+// installUSBDriver installs WinUSB driver via KneronPLUS SDK (libwdi).
+func installUSBDriver(installDir string) error {
+	return installKneronDriverViaSDK(installDir)
+}
+
+// installKneronDriverViaSDK uses the KneronPLUS SDK's built-in libwdi to
+// install WinUSB driver for all known Kneron devices. Must be called after
+// the Python venv with kp module is set up.
+func installKneronDriverViaSDK(installDir string) error {
+	venvPython := filepath.Join(installDir, "venv", "Scripts", "python.exe")
+	if _, err := os.Stat(venvPython); err != nil {
+		return fmt.Errorf("Python venv not found, cannot install driver")
+	}
+
+	// Use kp.core.install_driver_for_windows() for each known product ID
+	// KL520=0x100, KL720=0x720, KL720_LEGACY=0x200
+	script := `
+import sys
+try:
+    import kp
+    for pid in [kp.ProductId.KP_DEVICE_KL520, kp.ProductId.KP_DEVICE_KL720, kp.ProductId.KP_DEVICE_KL720_LEGACY]:
+        try:
+            kp.core.install_driver_for_windows(pid)
+            print(f"OK: driver installed for {pid.name}")
+        except Exception as e:
+            print(f"SKIP: {pid.name}: {e}")
+    print("DONE")
+except ImportError:
+    print("ERROR: kp module not available")
+    sys.exit(1)
+`
+	cmd := exec.Command(venvPython, "-c", script)
+	cmd.Dir = installDir
+	// Ensure kp can find its DLLs
+	cmd.Env = append(os.Environ(),
+		fmt.Sprintf("PATH=%s;%s;%s",
+			filepath.Join(installDir, "venv", "Lib", "site-packages", "kp", "lib"),
+			installDir,
+			os.Getenv("PATH")))
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("WinUSB driver install via KneronPLUS SDK failed: %s — please install manually using Zadig (https://zadig.akeo.ie/)", strings.TrimSpace(string(out)))
+	}
+
+	output := string(out)
+	if strings.Contains(output, "ERROR:") {
+		return fmt.Errorf("WinUSB driver install failed: %s — please install manually using Zadig (https://zadig.akeo.ie/)", strings.TrimSpace(output))
 	}
 
 	return nil