remove app animations to fix transition flash

Temporarily removed complex animations that were causing double-render flash.
Using simple hide/show approach during content loading instead.

src/main/assets/apps/shell/shell.lua

@@ -60,11 +60,8 @@ function loadAppContent_internal(app_id, app_path, skip_animation)
 
     -- Load app content using C++ function
     if loadAppContent then
-        -- Set opening animation BEFORE loading content to prevent flash
-        if not skip_animation then
-            app_container:SetClass("app-opening", true)
-            app_container:SetClass("app-closing", false)
-        end
+        -- Hide container before loading to prevent flash
+        app_container:SetClass("app-hidden", true)
 
         local success = loadAppContent(app_container, app_path)
         showLoading(false)
@@ -74,12 +71,8 @@ function loadAppContent_internal(app_id, app_path, skip_animation)
             current_app_path = app_path
             print("[Shell] App loaded: " .. app_id)
 
-            -- Remove animation class after it completes
-            if not skip_animation and setTimeout then
-                setTimeout(function()
-                    app_container:SetClass("app-opening", false)
-                end, 300)
-            end
+            -- Show container after content is loaded
+            app_container:SetClass("app-hidden", false)
 
             -- If home was loaded, populate apps dynamically
             if app_id == "home" then
@@ -139,20 +132,10 @@ end
 
 -- ===== NAVIGATION =====
 
--- Play closing animation then execute callback
+-- Execute callback for navigation (animations removed to fix flash)
 local function playCloseAnimation(callback)
-    if app_container and setTimeout then
-        app_container:SetClass("app-closing", true)
-        app_container:SetClass("app-opening", false)
-        setTimeout(function()
-            -- Don't remove app-closing yet - callback will load new content
-            -- and loadAppContent_internal will switch to app-opening
-            if callback then callback() end
-        end, 200)
-    else
-        -- No animation support, execute immediately
-        if callback then callback() end
-    end
+    -- Just execute callback immediately - loadAppContent handles hiding
+    if callback then callback() end
 end
 
 -- Go back to previous app