refactor(app): drive host config by value, not streams

AppConfigSource now carries plain values (ThemeSettings/ThemeMode/FeatureAccess)
instead of streams. The app renders them directly through the widget tree the
same way it renders everything else - App reads the theme from configSource (or
its AppBloc), and RootApp provides the FeatureAccess value (or the normal
StreamProvider). A host re-supplies a fresh AppConfigSource on each edit, so
reactivity comes from the normal rebuild; no stream subscriptions, no
AppThemeSettingsChanged/AppThemeModeChanged plumbing, no initial-seed field.

Author: SERDUN

lib/app/app_config_source.dart

@@ -4,24 +4,22 @@ import 'package:webtrit_phone/data/feature_access.dart';
 import 'package:webtrit_phone/theme/theme.dart';
 
 /// Live application configuration supplied by an external host (the theme
-/// configurator's realtime preview).
+/// configurator's realtime preview), passed down the widget tree like any other
+/// config.
 ///
-/// Every field is optional: when a source is provided the app follows it,
-/// otherwise it uses its own bootstrap-built defaults. This is a plain config
-/// source — it carries no notion of "embedding", so the app stays unaware of
-/// where it runs.
+/// Every field is optional: when present the app renders it, otherwise it uses
+/// its bootstrap-built defaults. These are plain values, not streams — the host
+/// re-supplies a new instance on each edit, so reactivity comes from the normal
+/// widget rebuild. The app carries no notion of "embedding".
 class AppConfigSource {
-  const AppConfigSource({this.themeSettings, this.themeMode, this.featureAccess, this.featureAccessInitial});
+  const AppConfigSource({this.themeSettings, this.themeMode, this.featureAccess});
 
-  /// Live theme appearance applied via `AppThemeSettingsChanged` (not persisted).
-  final Stream<ThemeSettings>? themeSettings;
+  /// Theme appearance to render instead of the app's own.
+  final ThemeSettings? themeSettings;
 
-  /// Live theme mode applied via `AppThemeModeChanged`, paired with [themeSettings].
-  final Stream<ThemeMode>? themeMode;
+  /// Theme mode (light/dark) to apply, paired with [themeSettings].
+  final ThemeMode? themeMode;
 
-  /// Reactive [FeatureAccess] that replaces the bootstrap-built configuration.
-  final Stream<FeatureAccess>? featureAccess;
-
-  /// First-frame [FeatureAccess] seed paired with [featureAccess].
-  final FeatureAccess? featureAccessInitial;
+  /// [FeatureAccess] to use instead of the bootstrap-built configuration.
+  final FeatureAccess? featureAccess;
 }

lib/app/view/app.dart

@@ -1,5 +1,3 @@
-import 'dart:async';
-
 import 'package:flutter/material.dart';
 
 import 'package:flutter_bloc/flutter_bloc.dart';
@@ -27,7 +25,7 @@ class App extends StatefulWidget {
   const App({super.key, this.configSource});
 
   /// Optional live config supplied by an external host (the configurator's
-  /// realtime preview); when present, the app follows its theme streams.
+  /// realtime preview); when present, the app renders its theme and feature config.
   final AppConfigSource? configSource;
 
   @override
@@ -38,9 +36,6 @@ class _AppState extends State<App> {
   late final AppBloc appBloc;
   late final AppRouter appRouter;
 
-  StreamSubscription<ThemeSettings>? _themeSettingsSubscription;
-  StreamSubscription<ThemeMode>? _themeModeSubscription;
-
   @override
   void initState() {
     super.initState();
@@ -93,13 +88,6 @@ class _AppState extends State<App> {
       initialTabResolver,
       featureAccess.checker,
     );
-
-    _themeSettingsSubscription = widget.configSource?.themeSettings?.listen(
-      (settings) => appBloc.add(AppThemeSettingsChanged(settings)),
-    );
-    _themeModeSubscription = widget.configSource?.themeMode?.listen(
-      (themeMode) => appBloc.add(AppThemeModeChanged(themeMode)),
-    );
   }
 
   @override
@@ -125,8 +113,6 @@ class _AppState extends State<App> {
 
   @override
   void dispose() {
-    _themeSettingsSubscription?.cancel();
-    _themeModeSubscription?.cancel();
     appBloc.close();
     super.dispose();
   }
@@ -137,11 +123,15 @@ class _AppState extends State<App> {
 
     final featureAccess = context.watch<FeatureAccess>();
 
+    // A host (the configurator's realtime preview) renders its own theme; the
+    // app falls back to its AppBloc theme otherwise.
+    final configSource = widget.configSource;
+
     final materialApp = BlocBuilder<AppBloc, AppState>(
       buildWhen: (previous, current) => previous.themeSettings != current.themeSettings,
       builder: (context, state) {
         return ThemeProvider(
-          settings: state.themeSettings,
+          settings: configSource?.themeSettings ?? state.themeSettings,
           lightDynamic: null,
           darkDynamic: null,
           child: BlocBuilder<AppBloc, AppState>(
@@ -151,7 +141,9 @@ class _AppState extends State<App> {
             builder: (context, state) {
               final themeProvider = ThemeProvider.of(context);
               final forcedMode = featureAccess.supportedConfig.themeMode;
-              final finalThemeMode = forcedMode == ThemeMode.system ? state.effectiveThemeMode : forcedMode;
+              final finalThemeMode = forcedMode == ThemeMode.system
+                  ? (configSource?.themeMode ?? state.effectiveThemeMode)
+                  : forcedMode;
 
               return MaterialApp.router(
                 locale: state.effectiveLocale,

lib/main.dart

@@ -90,11 +90,15 @@ class RootApp extends StatelessWidget {
         // Provides reactive [FeatureAccess] configuration synchronized with [SystemInfoRepository] and [RemoteConfigService].
         //
         // Initializes with bootstrap data and updates whenever system information or remote configuration changes.
-        StreamProvider<FeatureAccess>(
-          initialData: configSource?.featureAccessInitial ?? instanceRegistry.get<FeatureAccess>(),
-          create: (_) => configSource?.featureAccess ?? instanceRegistry.get<FeatureAccessStreamFactory>().create(),
-          updateShouldNotify: (previous, next) => previous != next,
-        ),
+        // A host (the configurator's realtime preview) overrides it with a plain value it re-supplies on edits.
+        if (configSource?.featureAccess != null)
+          Provider<FeatureAccess>.value(value: configSource!.featureAccess!)
+        else
+          StreamProvider<FeatureAccess>(
+            initialData: instanceRegistry.get<FeatureAccess>(),
+            create: (_) => instanceRegistry.get<FeatureAccessStreamFactory>().create(),
+            updateShouldNotify: (previous, next) => previous != next,
+          ),
         Provider<SecureStorage>(create: (_) => instanceRegistry.get()),
         Provider<AppPermissions>(create: (_) => instanceRegistry.get()),
         Provider<AppLogger>(create: (_) => instanceRegistry.get()),