feat: MVP implementation - Kiosk Browser

- Fullscreen WebView with immersive mode
- URL whitelist system
- Admin PIN-protected settings
- Boot receiver for auto-launch
- Idle timeout with homepage reset
- Lock Task Mode support
- Material Design 3 UI

Team: Pluto (coordinator), Margaret, Spirit

app/src/main/kotlin/farm/hobbs/kioskbrowser/BootReceiver.kt

@@ -0,0 +1,19 @@
+package farm.hobbs.kioskbrowser
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+
+class BootReceiver : BroadcastReceiver() {
+    override fun onReceive(context: Context, intent: Intent) {
+        if (intent.action == Intent.ACTION_BOOT_COMPLETED ||
+            intent.action == "android.intent.action.QUICKBOOT_POWERON") {
+            
+            val launchIntent = Intent(context, MainActivity::class.java).apply {
+                addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+                addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
+            }
+            context.startActivity(launchIntent)
+        }
+    }
+}