refactor: rename dashboards→webviews, unique applicationId per flavor

Each flavor gets applicationIdSuffix = ".<name>" so the Bravia
getApplicationList API returns a distinct URI per webview, enabling
Control4 to launch specific flavors independently.

BREAKING CHANGE: applicationId changed from cz.c3c.webviewkiosk to
cz.c3c.webviewkiosk.<flavor> — uninstall old app before reinstalling.
BuildConfig.DASHBOARD_URL renamed to WEBVIEW_URL.

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

app/src/main/java/cz/c3c/webviewkiosk/MainActivity.kt

@@ -50,7 +50,7 @@ class MainActivity : Activity() {
                 if (!request.isForMainFrame) return
                 lastLoadFailed = true
                 handler.postDelayed(
-                    { view.loadUrl(BuildConfig.DASHBOARD_URL) },
+                    { view.loadUrl(BuildConfig.WEBVIEW_URL) },
                     backoff.nextDelayMs(),
                 )
             }
@@ -58,7 +58,7 @@ class MainActivity : Activity() {
 
         setContentView(webView)
         hideSystemUi()
-        webView.loadUrl(BuildConfig.DASHBOARD_URL)
+        webView.loadUrl(BuildConfig.WEBVIEW_URL)
     }
 
     override fun onResume() {