fix: incluir o wallpaper padrao no bundle e mostrar na previa

O Flutter nao empacota subdirectorios de forma recursiva, e assets/logo/ nao estava listado no pubspec, portanto assets/logo/background.png nunca chegava ao bundle e o wallpaper padrao das conversas nao aparecia.

- pubspec: declara assets/logo/background.png
- chat_view: normaliza o path do asset
- settings_style_view: a previa passa a mostrar o wallpaper padrao quando nao ha imagem custom, com opacidade 0.3 e sem blur, em vez de ficar sem fundo

lib/pages/chat/chat_view.dart

@@ -377,7 +377,7 @@ class ChatView extends StatelessWidget {
                                     placeholder: (_) => Container(),
                                   )
                                 : Image.asset(
-                                    './assets/logo/background.png',
+                                    'assets/logo/background.png',
                                     fit: BoxFit.cover,
                                     height: MediaQuery.sizeOf(context).height,
                                     width: MediaQuery.sizeOf(context).width,

lib/pages/settings_style/settings_style_view.dart

@@ -176,21 +176,35 @@ class SettingsStyleView extends StatelessWidget {
                         child: Stack(
                           alignment: Alignment.center,
                           children: [
-                            if (accountConfig.wallpaperUrl != null)
                             Opacity(
-                                opacity: controller.wallpaperOpacity,
+                              opacity: accountConfig.wallpaperUrl != null
+                                  ? controller.wallpaperOpacity
+                                  : 0.3,
                               child: ImageFiltered(
                                 imageFilter: ImageFilter.blur(
-                                    sigmaX: controller.wallpaperBlur,
-                                    sigmaY: controller.wallpaperBlur,
+                                  sigmaX: accountConfig.wallpaperUrl != null
+                                      ? controller.wallpaperBlur
+                                      : 0.0,
+                                  sigmaY: accountConfig.wallpaperUrl != null
+                                      ? controller.wallpaperBlur
+                                      : 0.0,
+                                ),
+                                child: accountConfig.wallpaperUrl != null
+                                    ? MxcImage(
+                                        key: ValueKey(
+                                          accountConfig.wallpaperUrl,
                                         ),
-                                  child: MxcImage(
-                                    key: ValueKey(accountConfig.wallpaperUrl),
                                         uri: accountConfig.wallpaperUrl,
                                         fit: BoxFit.cover,
                                         isThumbnail: true,
                                         width: FluffyThemes.columnWidth * 2,
                                         height: 212,
+                                      )
+                                    : Image.asset(
+                                        'assets/logo/background.png',
+                                        fit: BoxFit.cover,
+                                        width: FluffyThemes.columnWidth * 2,
+                                        height: 212,
                                       ),
                               ),
                             ),
@@ -213,12 +227,10 @@ class SettingsStyleView extends StatelessWidget {
                                   ),
                                 ),
                                 Padding(
-                                  padding: EdgeInsets.only(
+                                  padding: const EdgeInsets.only(
                                     left: 12 + 12 + Avatar.defaultSize,
                                     right: 12,
-                                    top: accountConfig.wallpaperUrl == null
-                                        ? 0
-                                        : 12,
+                                    top: 12,
                                     bottom: 12,
                                   ),
                                   child: DecoratedBox(
@@ -246,12 +258,10 @@ class SettingsStyleView extends StatelessWidget {
                                 Align(
                                   alignment: Alignment.centerLeft,
                                   child: Padding(
-                                    padding: EdgeInsets.only(
+                                    padding: const EdgeInsets.only(
                                       right: 12,
                                       left: 12,
-                                      top: accountConfig.wallpaperUrl == null
-                                          ? 0
-                                          : 12,
+                                      top: 12,
                                       bottom: 12,
                                     ),
                                     child: Material(

pubspec.yaml

@@ -118,6 +118,7 @@ flutter:
   uses-material-design: true
   assets:
     - assets/
+    - assets/logo/background.png
     - assets/logo/mini/
     - assets/miniapps/
     - assets/sounds/