ui: constrain tier editor item scroll

frontend/src/views/TierEditorView.vue

@@ -2743,7 +2743,10 @@ onUnmounted(() => {
   object-fit: cover;
 }
 .sidebar {
+  --editor-sidebar-visible-offset: 136px;
   min-width: 0;
+  display: flex;
+  flex-direction: column;
   border: 1px solid var(--theme-border);
   background: linear-gradient(180deg, color-mix(in srgb, var(--theme-card-bg) 94%, transparent), color-mix(in srgb, var(--theme-card-bg-hover) 88%, transparent));
   border-radius: 22px;
@@ -2751,6 +2754,9 @@ onUnmounted(() => {
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
   position: sticky;
   top: 14px;
+  max-height: calc(100dvh - var(--editor-sidebar-visible-offset));
+  overflow: hidden;
+  overscroll-behavior: contain;
 }
 
 .dropzone--board {
@@ -3065,6 +3071,9 @@ onUnmounted(() => {
   color: var(--theme-text-faint);
 }
 .pool {
+  flex: 1 1 auto;
+  min-height: 0;
+  overflow-y: auto;
   display: grid;
   grid-template-columns: repeat(auto-fill, minmax(96px, 1fr));
   gap: 10px;
@@ -3259,8 +3268,11 @@ onUnmounted(() => {
   }
   .sidebar {
     position: static;
+    max-height: none;
+    overflow: visible;
   }
   .pool {
+    overflow: visible;
     grid-template-columns: repeat(6, minmax(0, 1fr));
     gap: 8px;
   }