feat(frontend): stripe the reclaimable-cache memory segment

At warning level the used segment turns threshold-yellow, which sat
next to the amber cache segment as one indistinguishable yellow mass.
Give the cache segment a vertical-stripe SVG pattern so the used/cache
split stays readable at every severity color. Stripes are vertical
because the bar's preserveAspectRatio=none scaling would shear a
diagonal texture.

frontend-modern/src/components/Workloads/StackedMemoryBar.tsx

@@ -1,4 +1,4 @@
-import { Show, For } from 'solid-js';
+import { Show, For, createUniqueId } from 'solid-js';
 import { AnimatedNumber } from '@/components/shared/AnimatedNumber';
 import { TooltipPortal } from '@/components/shared/TooltipPortal';
 import { formatPercent } from '@/utils/format';
@@ -8,6 +8,7 @@ import { useStackedMemoryBarState } from './useStackedMemoryBarState';
 export function StackedMemoryBar(props: StackedMemoryBarProps) {
   const state = useStackedMemoryBarState(props);
   const presentation = state.presentation;
+  const stripePatternId = createUniqueId();
   const swapBarWidth = () => String(Math.max(0, Math.min(presentation().swapBarPercent, 100)));
   const segmentEdge = (leftPercent: number, widthPercent: number) =>
     String(Math.max(0, Math.min(leftPercent + widthPercent, 100)));
@@ -28,6 +29,19 @@ export function StackedMemoryBar(props: StackedMemoryBarProps) {
           viewBox="0 0 100 100"
           preserveAspectRatio="none"
         >
+          {/* Vertical stripes only: the non-uniform viewBox scaling would
+              shear any diagonal texture. Keeps the reclaimable-cache segment
+              distinguishable from a warning-yellow used segment. */}
+          <defs>
+            <pattern
+              id={stripePatternId}
+              patternUnits="userSpaceOnUse"
+              width="2.5"
+              height="100"
+            >
+              <rect x="0" y="0" width="1.25" height="100" fill="rgba(217, 119, 6, 0.5)" />
+            </pattern>
+          </defs>
           <For each={presentation().segments}>
             {(segment, idx) => (
               <>
@@ -41,6 +55,18 @@ export function StackedMemoryBar(props: StackedMemoryBarProps) {
                   rx="3"
                   fill={segment.color}
                 />
+                <Show when={segment.striped}>
+                  <rect
+                    data-stacked-memory-stripes="true"
+                    class="metric-fill-geometry"
+                    x={String(Math.max(0, Math.min(segment.leftPercent, 100)))}
+                    y="0"
+                    width={String(Math.max(0, segment.widthPercent))}
+                    height="100"
+                    rx="3"
+                    fill={`url(#${stripePatternId})`}
+                  />
+                </Show>
                 <Show when={idx() < presentation().segments.length - 1}>
                   <line
                     class="metric-fill-divider"

frontend-modern/src/components/Workloads/__tests__/stackedMemoryBarModel.test.ts

@@ -17,6 +17,9 @@ describe('buildStackedMemoryBarPresentation', () => {
     ]);
     expect(presentation.segments[1].leftPercent).toBeCloseTo(25);
     expect(presentation.segments[1].widthPercent).toBeCloseTo(37.5);
+    // Cache is textured so it never blends into a warning-yellow used segment.
+    expect(presentation.segments[1].striped).toBe(true);
+    expect(presentation.segments[0].striped).toBeUndefined();
 
     const rows = Object.fromEntries(presentation.tooltipRows.map((row) => [row.label, row.value]));
     expect(rows['Used']).toBe('4.00 GB');

frontend-modern/src/components/Workloads/stackedMemoryBarModel.ts

@@ -29,6 +29,8 @@ export interface StackedMemorySegment {
   label: string;
   leftPercent: number;
   widthPercent: number;
+  /** Diagonal-stripe texture so reclaimable cache stays distinguishable from a warning-yellow used segment. */
+  striped?: boolean;
 }
 
 export interface StackedMemoryTooltipRow {
@@ -129,6 +131,7 @@ function getSegments(
       label: 'Reclaimable',
       leftPercent: usedPercent,
       widthPercent: cachePercent,
+      striped: true,
     });
   }