fix timeline overflowing dropdowns, more resonable z-indices (#4071)

web/src/lib/components/shared-components/context-menu/context-menu.svelte

@@ -23,7 +23,7 @@
 <div
   transition:slide={{ duration: 200, easing: quintOut }}
   bind:this={menuElement}
-  class="absolute z-[99999] w-[200px] overflow-hidden rounded-lg shadow-lg"
+  class="absolute w-[200px] overflow-hidden rounded-lg shadow-lg"
   style="left: {left}px; top: {top}px;"
   role="menu"
   use:clickOutside

web/src/lib/components/shared-components/scrollbar/scrollbar.svelte

@@ -59,7 +59,7 @@
 {#if $assetStore.timelineHeight > height}
   <div
     id="immich-scrubbable-scrollbar"
-    class="fixed right-0 z-[100] select-none bg-immich-bg hover:cursor-row-resize"
+    class="fixed right-0 z-[1] select-none bg-immich-bg hover:cursor-row-resize"
     style:width={isDragging ? '100vw' : '60px'}
     style:height={height + 'px'}
     style:background-color={isDragging ? 'transparent' : 'transparent'}