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

src/main/assets/apps/shell/shell.rml

@@ -51,38 +51,9 @@
             background-color: #121212;
         }
 
-        /* App launch/close animations */
-        .app-opening {
-            animation: 0.25s back-out app-open;
-        }
-
-        .app-closing {
-            animation: 0.2s quadratic-in app-close;
-            /* Keep at end state after animation */
+        /* App visibility - simple hide/show without complex animations */
+        .app-hidden {
             opacity: 0;
-            transform: scale(0.8);
-        }
-
-        @keyframes app-open {
-            from {
-                opacity: 0;
-                transform: scale(0.8);
-            }
-            to {
-                opacity: 1;
-                transform: scale(1.0);
-            }
-        }
-
-        @keyframes app-close {
-            from {
-                opacity: 1;
-                transform: scale(1.0);
-            }
-            to {
-                opacity: 0;
-                transform: scale(0.8);
-            }
         }
 
         /* System navigation bar at bottom - always visible */