fix(ui): fix scrolling and consistent header height on small displays

- Fix scrolling in edit-menu, settings-menu, classes-menu, update-menu, custom-menu
  * Change .main-content from overflow:hidden to overflow-y:auto
  * Add flex:1 1 auto and overflow-y:auto to .menu-element-container
  * Add flex properties to .result-list for proper scrolling

- Fix custom-menu button positioning
  * Update createMenuElement to detect container elements (nav/section)
  * Use appendChild for containers instead of insertBefore
  * Remove placeholder workaround in createDynamicMenu

- Fix inconsistent header height across menus
  * Set min-height: 100px for all headers (was 50px)
  * Ensure mobile breakpoint also uses min-height: 100px

All menus now have consistent header height and proper scrolling on small displays.

Author: KristjanESPERANTO

remote.css

@@ -67,7 +67,7 @@ body {
   margin-inline: auto;
   width: 90%;
   max-width: 85%;
-  min-height: 50px;
+  min-height: 100px;
   display: flex;
   align-items: center;
   justify-content: space-between;
@@ -160,6 +160,7 @@ body {
     max-width: 95%;
     font-size: 1.3em;
     padding: 0.8em 0;
+    min-height: 100px;
     gap: 0.3em;
   }
 
@@ -216,7 +217,8 @@ a {
   display: flex;
   flex-direction: column;
   min-height: 0;
-  overflow: hidden;
+  overflow-y: auto;
+  overflow-x: hidden;
 }
 
 .menu-content {
@@ -268,6 +270,10 @@ a {
   width: 95%;
   max-width: 900px;
   margin-inline: auto;
+  flex: 1 1 auto;
+  display: flex;
+  flex-direction: column;
+  min-height: 0;
 }
 
 .results:last-child {
@@ -303,10 +309,11 @@ a {
 .menu-element-container {
   display: flex;
   flex-direction: column;
-  flex: 0 0 auto;
+  flex: 1 1 auto;
   width: 100%;
   max-width: 1400px;
   margin-inline: auto;
+  overflow-y: auto;
 }
 
 .one-line {

remote.js

@@ -2075,7 +2075,16 @@ const Remote = {
       item.classList.add("hidden");
     }
 
-    insertAfter.parentNode.insertBefore(item, insertAfter.nextSibling);
+    /*
+     * Insert element: if insertAfter is a container (nav/section), append to it
+     * Otherwise insert after the specified element
+     */
+    if (insertAfter.tagName === "NAV" || insertAfter.tagName === "SECTION" ||
+      insertAfter.classList.contains("menu-element-container")) {
+      insertAfter.append(item);
+    } else {
+      insertAfter.parentNode.insertBefore(item, insertAfter.nextSibling);
+    }
 
     if ("items" in content) {
       for (const index of content.items) {
@@ -2120,7 +2129,7 @@ const Remote = {
 
       // Create menu items inside the new nav
       for (const item of content.items) {
-        this.createMenuElement(item, content.id, nav.lastChild || nav);
+        this.createMenuElement(item, content.id, nav);
       }
     }
   }