Add v9.1.1: Device registry and remote blocking system

- Implement DeviceRegistry for remote device management
- Add dashboard for device tracking and blocking
- Remote device blocking capability with admin control
- Support for device aliasing and notes
- Enhanced device management interface
- Dashboard with real-time device status
- Configurable registry URL in build config

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

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

app/src/main/java/com/streamplayer/MainActivity.java

@@ -8,6 +8,7 @@ import android.view.View;
 import android.widget.ProgressBar;
 import android.widget.TextView;
 import android.widget.Toast;
+import android.text.TextUtils;
 
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.recyclerview.widget.GridLayoutManager;
@@ -40,6 +41,8 @@ public class MainActivity extends AppCompatActivity {
     private SectionEntry currentSection;
     private UpdateManager updateManager;
     private AlertDialog updateDialog;
+    private AlertDialog blockedDialog;
+    private DeviceRegistry deviceRegistry;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -85,6 +88,28 @@ public class MainActivity extends AppCompatActivity {
                         Toast.LENGTH_SHORT).show();
             }
         });
+
+        deviceRegistry = new DeviceRegistry(this);
+        deviceRegistry.syncDevice(new DeviceRegistry.Callback() {
+            @Override
+            public void onAllowed() {
+                // Device authorized, continue normally.
+            }
+
+            @Override
+            public void onBlocked(String reason) {
+                showBlockedDialog(reason);
+            }
+
+            @Override
+            public void onError(String message) {
+                if (!TextUtils.isEmpty(message)) {
+                    Toast.makeText(MainActivity.this,
+                            getString(R.string.device_registry_error, message),
+                            Toast.LENGTH_SHORT).show();
+                }
+            }
+        });
     }
 
     @Override
@@ -101,9 +126,15 @@ public class MainActivity extends AppCompatActivity {
         if (updateDialog != null && updateDialog.isShowing()) {
             updateDialog.dismiss();
         }
+        if (blockedDialog != null && blockedDialog.isShowing()) {
+            blockedDialog.dismiss();
+        }
         if (updateManager != null) {
             updateManager.release();
         }
+        if (deviceRegistry != null) {
+            deviceRegistry.release();
+        }
     }
 
     private void selectSection(int index) {
@@ -276,6 +307,25 @@ public class MainActivity extends AppCompatActivity {
         }
     }
 
+    private void showBlockedDialog(String reason) {
+        if (isFinishing()) {
+            return;
+        }
+        String finalReason = TextUtils.isEmpty(reason)
+                ? getString(R.string.device_blocked_default_reason)
+                : reason;
+        if (blockedDialog != null && blockedDialog.isShowing()) {
+            blockedDialog.dismiss();
+        }
+        blockedDialog = new AlertDialog.Builder(this)
+                .setTitle(R.string.device_blocked_title)
+                .setMessage(getString(R.string.device_blocked_message, finalReason))
+                .setCancelable(false)
+                .setPositiveButton(R.string.device_blocked_close,
+                        (dialog, which) -> finish())
+                .show();
+    }
+
     private int getSpanCount() {
         return getResources().getInteger(R.integer.channel_grid_span);
     }