fix(nav): inventory is a spoke off the home hub — back arrow, no duplicate drawer

The inventory screen carried its own const AppDrawer() (no marketEnabled),
so opening the menu from inventory greyed out market/chat/profile — the
recurring 'phase 1' look. It was also reached via go() (route replace),
which is why it showed a hamburger instead of a back arrow like the market.

Make it coherent with the market: reach inventory via push() (from the
home card and the drawer), and drop its drawer so the AppBar shows a back
arrow returning to the home hub. The drawer now lives only on the home
screen, which always passes marketEnabled — the wrong-drawer bug class is
gone. Update the home_screen test to assert the spoke has a back arrow and
no hamburger.

apps/app_seeds/lib/ui/home_screen.dart

@@ -77,7 +77,7 @@ class HomeScreen extends StatelessWidget {
                       icon: Icons.inventory_2_outlined,
                       label: t.home.yourInventory,
                       subtitle: t.home.yourInventorySubtitle,
-                      onTap: () => context.go('/inventory'),
+                      onTap: () => context.push('/inventory'),
                     ),
                     const SizedBox(height: 16),
                     _OutlinedMenuCard(