feat(appstore): rebrand as SilverSHELL AppStore client

- applicationId: uk.silverlabs.silverdroid → uk.silverlabs.appstore
- app_name: SilverDROID → SilverSHELL AppStore
- user agent: SilverDROID/1.0 → SilverAppStore/1.0
- versionCode/versionName: override via Gradle -P args for CI builds

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/src/main/kotlin/uk/silverlabs/silverdroid/ui/webview/WasmWebView.kt

@@ -22,7 +22,8 @@ fun WasmWebView(
     url: String,
     appName: String,
     onBackPressed: () -> Unit,
-    modifier: Modifier = Modifier
+    modifier: Modifier = Modifier,
+    jsInterface: AppStoreJsBridge? = null
 ) {
     var webView by remember { mutableStateOf<WebView?>(null) }
     var isLoading by remember { mutableStateOf(true) }
@@ -113,7 +114,12 @@ fun WasmWebView(
 
                         // User agent (modern)
                         settings.userAgentString = settings.userAgentString +
-                                " SilverDROID/1.0 (PWA/WASM Launcher)"
+                                " SilverAppStore/1.0 (AppStore Client)"
+
+                        // Wire AppStore JS bridge so Blazor can call native install
+                        jsInterface?.let {
+                            addJavascriptInterface(it, AppStoreJsBridge.BRIDGE_NAME)
+                        }
 
                         // Enable wide viewport
                         settings.useWideViewPort = true