refactor: use tailwind custom colors for themes

Use tailwind v4 @theme block so we can use bg-layer-0 instead of
bg-[--layer-0] for theme colors.

app/src/lib/sidebar/Panel.svelte

@@ -43,7 +43,7 @@
 
 <style>
   header {
-    border-bottom: solid thin var(--outline);
+    border-bottom: solid thin var(--color-outline);
     height: 70px;
     display: flex;
     align-items: center;

app/src/lib/sidebar/Sidebar.svelte

@@ -8,7 +8,6 @@
 <div class="wrapper" class:visible={state.activePanel.value}>
   <div class="tabs">
     <button aria-label="Close" onclick={() => state.toggleOpen()}>
-      <span class="icon-[tabler--settings]"></span>
       <span class="absolute i-[tabler--chevron-left] w-6 h-6 block"></span>
     </button>
     {#each state.keys as panelId (panelId)}
@@ -45,7 +44,7 @@
   }
 
   .content {
-    background: var(--layer-1);
+    background: var(--color-layer-1);
     z-index: 10;
     position: relative;
     max-height: 100vh;
@@ -55,7 +54,7 @@
   .tabs {
     display: flex;
     flex-direction: column;
-    border-right: solid thin var(--outline);
+    border-right: solid thin var(--color-outline);
   }
 
   .tabs > button {
@@ -66,9 +65,9 @@
     border: none;
     display: flex;
     align-items: center;
-    border-bottom: solid thin var(--outline);
-    border-left: solid thin var(--outline);
-    background: var(--layer-1);
+    border-bottom: solid thin var(--color-outline);
+    border-left: solid thin var(--color-outline);
+    background: var(--color-layer-1);
   }
 
   .tabs > button > span {
@@ -76,7 +75,7 @@
   }
 
   .tabs > button.active {
-    background: var(--layer-2);
+    background: var(--color-layer-2);
   }
 
   .tabs > button.active span {

app/src/lib/sidebar/panels/BenchmarkPanel.svelte

@@ -8,7 +8,7 @@
   import { humanizeDuration } from '$lib/helpers';
   import { localState } from '$lib/helpers/localState.svelte';
   import Monitor from '$lib/performance/Monitor.svelte';
-  import { Float } from '@nodarium/ui';
+  import { InputNumber } from '@nodarium/ui';
   import { writable } from 'svelte/store';
 
   function calculateStandardDeviation(array: number[]) {
@@ -125,7 +125,7 @@
     </progress>
   {:else}
     <label for="bench-samples">Samples</label>
-    <Float id="bench-sample" bind:value={amount.value} max={1000} />
+    <InputNumber id="bench-sample" bind:value={amount.value} max={1000} step={1} />
     <button onclick={benchmark} disabled={isRunning}>start</button>
   {/if}
 </div>
@@ -138,7 +138,7 @@
     gap: 1em;
   }
   .monitor-wrapper {
-    border: solid thin var(--outline);
+    border: solid thin var(--color-outline);
     border-bottom: none;
   }
   i {