fix: improve navigation stack and ensure square cover aspect ratios

Navigation fixes:
- Change goNamed to pushNamed in all library browser pages
- Maintains proper back navigation stack
- Back button now goes step by step instead of to beginning
- Prevents app from closing when navigating back from book detail

Grid layout fixes:
- Book covers are now always square (1.0 aspect ratio)
- Overall card aspect ratio is 0.75 to provide space for text
- Wrap cover in AspectRatio widget instead of using Expanded
- Ensures title and author info always visible below covers
- Fixes issue where book info was missing in series view

lib/features/library_browser/view/library_genres_page.dart

@@ -86,7 +86,7 @@ class GenreListTile extends StatelessWidget {
         trailing: const Icon(Icons.chevron_right),
         onTap: () {
           // Navigate to filtered items page with genre filter
-          context.goNamed(
+          context.pushNamed(
             Routes.libraryFiltered.name,
             extra: {
               'filter': GenreFilter(genre),