feat: add execution overlay visual states to DiagramNode

DiagramNode now accepts executionState and overlayActive props to render
execution status: green tint + checkmark badge for completed nodes, red
tint + exclamation badge for failed nodes, dimmed opacity for skipped
nodes. Duration is shown at bottom-right, and a drill-down arrow appears
for sub-route failures.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/components/ProcessDiagram/DiagramNode.tsx

@@ -1,5 +1,6 @@
 import type { DiagramNode as DiagramNodeType } from '../../api/queries/diagrams';
 import type { NodeConfig } from './types';
+import type { NodeExecutionState } from '../ExecutionDiagram/types';
 import { colorForType, iconForType } from './node-colors';
 import { ConfigBadge } from './ConfigBadge';
 
@@ -11,14 +12,23 @@ interface DiagramNodeProps {
   isHovered: boolean;
   isSelected: boolean;
   config?: NodeConfig;
+  executionState?: NodeExecutionState;
+  overlayActive?: boolean;
   onClick: () => void;
   onDoubleClick?: () => void;
   onMouseEnter: () => void;
   onMouseLeave: () => void;
 }
 
+function formatDuration(ms: number): string {
+  if (ms < 1000) return `${ms}ms`;
+  return `${(ms / 1000).toFixed(1)}s`;
+}
+
 export function DiagramNode({
-  node, isHovered, isSelected, config, onClick, onDoubleClick, onMouseEnter, onMouseLeave,
+  node, isHovered, isSelected, config,
+  executionState, overlayActive,
+  onClick, onDoubleClick, onMouseEnter, onMouseLeave,
 }: DiagramNodeProps) {
   const x = node.x ?? 0;
   const y = node.y ?? 0;
@@ -31,6 +41,33 @@ export function DiagramNode({
   const typeName = node.type?.replace(/^EIP_/, '').replace(/_/g, ' ') ?? '';
   const detail = node.label || '';
 
+  // Overlay state derivation
+  const isCompleted = executionState?.status === 'COMPLETED';
+  const isFailed = executionState?.status === 'FAILED';
+  const isSkipped = overlayActive && !executionState;
+
+  // Colors based on execution state
+  let cardFill = isHovered ? '#F5F0EA' : 'white';
+  let borderStroke = isHovered || isSelected ? color : '#E4DFD8';
+  let borderWidth = isHovered || isSelected ? 1.5 : 1;
+  let topBarColor = color;
+  let labelColor = '#1A1612';
+
+  if (isCompleted) {
+    cardFill = isHovered ? '#E4F5E6' : '#F0F9F1';
+    borderStroke = '#3D7C47';
+    borderWidth = 1.5;
+    topBarColor = '#3D7C47';
+  } else if (isFailed) {
+    cardFill = isHovered ? '#F9E4E1' : '#FDF2F0';
+    borderStroke = '#C0392B';
+    borderWidth = 2;
+    topBarColor = '#C0392B';
+    labelColor = '#C0392B';
+  }
+
+  const statusColor = isCompleted ? '#3D7C47' : isFailed ? '#C0392B' : undefined;
+
   return (
     <g
       data-node-id={node.id}
@@ -40,6 +77,7 @@ export function DiagramNode({
       onMouseEnter={onMouseEnter}
       onMouseLeave={onMouseLeave}
       style={{ cursor: 'pointer' }}
+      opacity={isSkipped ? 0.35 : undefined}
     >
       {/* Selection ring */}
       {isSelected && (
@@ -62,34 +100,93 @@ export function DiagramNode({
         width={w}
         height={h}
         rx={CORNER_RADIUS}
-        fill={isHovered ? '#F5F0EA' : 'white'}
-        stroke={isHovered || isSelected ? color : '#E4DFD8'}
-        strokeWidth={isHovered || isSelected ? 1.5 : 1}
+        fill={cardFill}
+        stroke={borderStroke}
+        strokeWidth={borderWidth}
       />
 
       {/* Colored top bar */}
-      <rect x={0} y={0} width={w} height={TOP_BAR_HEIGHT} rx={CORNER_RADIUS} fill={color} />
-      <rect x={CORNER_RADIUS} y={0} width={w - CORNER_RADIUS * 2} height={TOP_BAR_HEIGHT} fill={color} />
+      <rect x={0} y={0} width={w} height={TOP_BAR_HEIGHT} rx={CORNER_RADIUS} fill={topBarColor} />
+      <rect x={CORNER_RADIUS} y={0} width={w - CORNER_RADIUS * 2} height={TOP_BAR_HEIGHT} fill={topBarColor} />
 
       {/* Icon */}
-      <text x={14} y={h / 2 + 6} fill={color} fontSize={14}>
+      <text x={14} y={h / 2 + 6} fill={statusColor ?? color} fontSize={14}>
         {icon}
       </text>
 
       {/* Type name */}
-      <text x={32} y={h / 2 + 1} fill="#1A1612" fontSize={11} fontWeight={600}>
+      <text x={32} y={h / 2 + 1} fill={labelColor} fontSize={11} fontWeight={600}>
         {typeName}
       </text>
 
       {/* Detail label (truncated) */}
       {detail && detail !== typeName && (
-        <text x={32} y={h / 2 + 14} fill="#5C5347" fontSize={10}>
+        <text x={32} y={h / 2 + 14} fill={isFailed ? '#C0392B' : '#5C5347'} fontSize={10}>
           {detail.length > 22 ? detail.slice(0, 20) + '...' : detail}
         </text>
       )}
 
       {/* Config badges */}
       {config && <ConfigBadge nodeWidth={w} config={config} />}
+
+      {/* Execution overlay: status badge at top-right */}
+      {isCompleted && (
+        <>
+          <circle cx={w - 8} cy={-8} r={8} fill="#3D7C47" />
+          <text
+            x={w - 8}
+            y={-4}
+            textAnchor="middle"
+            fill="white"
+            fontSize={11}
+            fontWeight={700}
+          >
+            &#x2713;
+          </text>
+        </>
+      )}
+      {isFailed && (
+        <>
+          <circle cx={w - 8} cy={-8} r={8} fill="#C0392B" />
+          <text
+            x={w - 8}
+            y={-4}
+            textAnchor="middle"
+            fill="white"
+            fontSize={12}
+            fontWeight={700}
+          >
+            !
+          </text>
+        </>
+      )}
+
+      {/* Execution overlay: duration text at bottom-right */}
+      {executionState && statusColor && (
+        <text
+          x={w - 6}
+          y={h - 4}
+          textAnchor="end"
+          fill={statusColor}
+          fontSize={9}
+          fontWeight={500}
+        >
+          {formatDuration(executionState.durationMs)}
+        </text>
+      )}
+
+      {/* Sub-route failure: drill-down arrow at bottom-left */}
+      {isFailed && executionState?.subRouteFailed && (
+        <text
+          x={6}
+          y={h - 4}
+          fill="#C0392B"
+          fontSize={11}
+          fontWeight={700}
+        >
+          &#x21B3;
+        </text>
+      )}
     </g>
   );
 }