refactor: AgentHealth slide-in detail panel and richer stat cards

- Instance detail now opens in a DetailPanel (slide-in from right)
  with Overview and Performance tabs instead of navigating away
- Stat strip matches mock design: 5 cards with colored StatusDot
  breakdowns, labeled states (live/stale/dead, healthy/degraded/critical)
- Active Routes shows colored ratio (green/yellow/red) based on state
- Groups renamed to Applications
- StatCard value/detail props now accept ReactNode for rich content

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

src/design-system/primitives/StatCard/StatCard.tsx

@@ -1,10 +1,11 @@
 import styles from './StatCard.module.css'
 import { Sparkline } from '../Sparkline/Sparkline'
+import type { ReactNode } from 'react'
 
 interface StatCardProps {
   label: string
-  value: string | number
-  detail?: string
+  value: ReactNode
+  detail?: ReactNode
   trend?: 'up' | 'down' | 'neutral'
   trendValue?: string
   accent?: 'amber' | 'success' | 'warning' | 'error' | 'running'

src/pages/AgentHealth/AgentHealth.module.css

@@ -10,11 +10,27 @@
 /* Stat strip */
 .statStrip {
   display: grid;
-  grid-template-columns: repeat(6, 1fr);
+  grid-template-columns: repeat(5, 1fr);
   gap: 10px;
   margin-bottom: 16px;
 }
 
+/* Stat breakdown with colored dots */
+.breakdown {
+  display: flex;
+  gap: 8px;
+  font-size: 11px;
+  font-family: var(--font-mono);
+}
+
+.bpLive { color: var(--success); display: inline-flex; align-items: center; gap: 3px; }
+.bpStale { color: var(--warning); display: inline-flex; align-items: center; gap: 3px; }
+.bpDead { color: var(--error); display: inline-flex; align-items: center; gap: 3px; }
+
+.routesSuccess { color: var(--success); }
+.routesWarning { color: var(--warning); }
+.routesError { color: var(--error); }
+
 /* Scope breadcrumb trail */
 .scopeTrail {
   display: flex;
@@ -178,11 +194,6 @@
   box-shadow: inset 3px 0 0 var(--amber);
 }
 
-/* Chart expansion row */
-.chartRow td {
-  padding: 0;
-}
-
 /* Instance fields */
 .instanceName {
   font-weight: 600;
@@ -211,17 +222,35 @@
   white-space: nowrap;
 }
 
-/* Instance expanded charts */
-.instanceCharts {
-  display: grid;
-  grid-template-columns: 1fr 1fr;
+/* Detail panel content */
+.detailContent {
+  display: flex;
+  flex-direction: column;
   gap: 12px;
-  padding: 12px 16px;
-  background: var(--bg-raised);
-  border-top: 1px solid var(--border-subtle);
+}
+
+.detailRow {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  font-size: 12px;
+  font-family: var(--font-body);
+  padding: 4px 0;
   border-bottom: 1px solid var(--border-subtle);
 }
 
+.detailLabel {
+  color: var(--text-muted);
+  font-weight: 500;
+}
+
+.detailProgress {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 140px;
+}
+
 .chartPanel {
   display: flex;
   flex-direction: column;

src/pages/AgentHealth/AgentHealth.tsx

@@ -1,5 +1,5 @@
-import { useMemo } from 'react'
-import { useParams, useNavigate, Link } from 'react-router-dom'
+import { useState, useMemo } from 'react'
+import { useParams, Link } from 'react-router-dom'
 import styles from './AgentHealth.module.css'
 
 // Layout
@@ -11,12 +11,14 @@ import { TopBar } from '../../design-system/layout/TopBar/TopBar'
 import { GroupCard } from '../../design-system/composites/GroupCard/GroupCard'
 import { LineChart } from '../../design-system/composites/LineChart/LineChart'
 import { EventFeed } from '../../design-system/composites/EventFeed/EventFeed'
+import { DetailPanel } from '../../design-system/composites/DetailPanel/DetailPanel'
 
 // Primitives
 import { StatusDot } from '../../design-system/primitives/StatusDot/StatusDot'
 import { MonoText } from '../../design-system/primitives/MonoText/MonoText'
 import { Badge } from '../../design-system/primitives/Badge/Badge'
 import { StatCard } from '../../design-system/primitives/StatCard/StatCard'
+import { ProgressBar } from '../../design-system/primitives/ProgressBar/ProgressBar'
 
 // Global filters
 import { useGlobalFilters } from '../../design-system/providers/GlobalFilterProvider'
@@ -31,13 +33,11 @@ import { agentEvents } from '../../mocks/agentEvents'
 type Scope =
   | { level: 'all' }
   | { level: 'app'; appId: string }
-  | { level: 'instance'; appId: string; instanceId: string }
 
 function useScope(): Scope {
   const { '*': rest } = useParams()
   const segments = rest?.split('/').filter(Boolean) ?? []
-  if (segments.length >= 2) return { level: 'instance', appId: segments[0], instanceId: segments[1] }
-  if (segments.length === 1) return { level: 'app', appId: segments[0] }
+  if (segments.length >= 1) return { level: 'app', appId: segments[0] }
   return { level: 'all' }
 }
 
@@ -106,11 +106,8 @@ function buildBreadcrumb(scope: Scope) {
     { label: 'Applications', href: '/apps' },
     { label: 'Agents', href: '/agents' },
   ]
-  if (scope.level === 'app' || scope.level === 'instance') {
-    crumbs.push({ label: scope.appId, href: `/agents/${scope.appId}` })
-  }
-  if (scope.level === 'instance') {
-    crumbs.push({ label: scope.instanceId })
+  if (scope.level === 'app') {
+    crumbs.push({ label: scope.appId })
   }
   return crumbs
 }
@@ -119,14 +116,14 @@ function buildBreadcrumb(scope: Scope) {
 
 export function AgentHealth() {
   const scope = useScope()
-  const navigate = useNavigate()
   const { isInTimeRange } = useGlobalFilters()
+  const [selectedInstance, setSelectedInstance] = useState<AgentHealthData | null>(null)
+  const [panelOpen, setPanelOpen] = useState(false)
 
   // Filter agents by scope
   const filteredAgents = useMemo(() => {
     if (scope.level === 'all') return agents
-    if (scope.level === 'app') return agents.filter((a) => a.appId === scope.appId)
-    return agents.filter((a) => a.appId === scope.appId && a.id === scope.instanceId)
+    return agents.filter((a) => a.appId === scope.appId)
   }, [scope])
 
   const groups = useMemo(() => groupByApp(filteredAgents), [filteredAgents])
@@ -138,18 +135,132 @@ export function AgentHealth() {
   const deadCount = filteredAgents.filter((a) => a.status === 'dead').length
   const totalTps = filteredAgents.reduce((s, a) => s + a.tps, 0)
   const totalActiveRoutes = filteredAgents.reduce((s, a) => s + a.activeRoutes, 0)
+  const totalRoutes = filteredAgents.reduce((s, a) => s + a.totalRoutes, 0)
 
   // Filter events by global time range
   const filteredEvents = agentEvents.filter((e) => isInTimeRange(e.timestamp))
 
-  // Single instance for expanded charts
-  const singleInstance = scope.level === 'instance' ? filteredAgents[0] : null
-  const trendData = singleInstance ? buildTrendData(singleInstance) : null
+  // Build trend data for selected instance
+  const trendData = selectedInstance ? buildTrendData(selectedInstance) : null
+
+  function handleInstanceClick(inst: AgentHealthData) {
+    setSelectedInstance(inst)
+    setPanelOpen(true)
+  }
+
+  // Detail panel tabs
+  const detailTabs = selectedInstance
+    ? [
+        {
+          label: 'Overview',
+          value: 'overview',
+          content: (
+            <div className={styles.detailContent}>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Status</span>
+                <Badge
+                  label={selectedInstance.status.toUpperCase()}
+                  color={selectedInstance.status === 'live' ? 'success' : selectedInstance.status === 'stale' ? 'warning' : 'error'}
+                />
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Application</span>
+                <MonoText size="xs">{selectedInstance.appId}</MonoText>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Version</span>
+                <MonoText size="xs">{selectedInstance.version}</MonoText>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Uptime</span>
+                <MonoText size="xs">{selectedInstance.uptime}</MonoText>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Last Seen</span>
+                <MonoText size="xs">{selectedInstance.lastSeen}</MonoText>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Throughput</span>
+                <MonoText size="xs">{selectedInstance.tps.toFixed(1)}/s</MonoText>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Errors</span>
+                <MonoText size="xs" className={selectedInstance.errorRate ? styles.instanceError : undefined}>
+                  {selectedInstance.errorRate ?? '0 err/h'}
+                </MonoText>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Routes</span>
+                <span>{selectedInstance.activeRoutes}/{selectedInstance.totalRoutes} active</span>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>Memory</span>
+                <div className={styles.detailProgress}>
+                  <ProgressBar
+                    value={selectedInstance.memoryUsagePct}
+                    variant={selectedInstance.memoryUsagePct > 85 ? 'error' : selectedInstance.memoryUsagePct > 70 ? 'warning' : 'success'}
+                  />
+                  <MonoText size="xs">{selectedInstance.memoryUsagePct}%</MonoText>
+                </div>
+              </div>
+              <div className={styles.detailRow}>
+                <span className={styles.detailLabel}>CPU</span>
+                <div className={styles.detailProgress}>
+                  <ProgressBar
+                    value={selectedInstance.cpuUsagePct}
+                    variant={selectedInstance.cpuUsagePct > 85 ? 'error' : selectedInstance.cpuUsagePct > 70 ? 'warning' : 'success'}
+                  />
+                  <MonoText size="xs">{selectedInstance.cpuUsagePct}%</MonoText>
+                </div>
+              </div>
+            </div>
+          ),
+        },
+        {
+          label: 'Performance',
+          value: 'performance',
+          content: trendData ? (
+            <div className={styles.detailContent}>
+              <div className={styles.chartPanel}>
+                <div className={styles.chartTitle}>Throughput (msg/s)</div>
+                <LineChart
+                  series={[{ label: 'tps', data: trendData.throughput }]}
+                  height={160}
+                  width={360}
+                  yLabel="msg/s"
+                />
+              </div>
+              <div className={styles.chartPanel}>
+                <div className={styles.chartTitle}>Error Rate (err/h)</div>
+                <LineChart
+                  series={[{ label: 'errors', data: trendData.errorRate, color: 'var(--error)' }]}
+                  height={160}
+                  width={360}
+                  yLabel="err/h"
+                />
+              </div>
+            </div>
+          ) : null,
+        },
+      ]
+    : []
 
   const isFullWidth = scope.level !== 'all'
 
   return (
-    <AppShell sidebar={<Sidebar apps={SIDEBAR_APPS} />}>
+    <AppShell
+      sidebar={<Sidebar apps={SIDEBAR_APPS} />}
+      detail={
+        selectedInstance ? (
+          <DetailPanel
+            open={panelOpen}
+            onClose={() => setPanelOpen(false)}
+            title={selectedInstance.name}
+            tabs={detailTabs}
+          />
+        ) : undefined
+      }
+    >
       <TopBar
         breadcrumb={buildBreadcrumb(scope)}
         environment="PRODUCTION"
@@ -159,35 +270,65 @@ export function AgentHealth() {
       <div className={styles.content}>
         {/* Stat strip */}
         <div className={styles.statStrip}>
-          <StatCard label="Total Instances" value={String(totalInstances)} />
-          <StatCard label="Live" value={String(liveCount)} accent="success" />
-          <StatCard label="Stale" value={String(staleCount)} accent={staleCount > 0 ? 'warning' : undefined} />
-          <StatCard label="Dead" value={String(deadCount)} accent={deadCount > 0 ? 'error' : undefined} />
-          <StatCard label="Total TPS" value={`${totalTps.toFixed(1)}/s`} />
-          <StatCard label="Active Routes" value={String(totalActiveRoutes)} />
+          <StatCard
+            label="Total Agents"
+            value={String(totalInstances)}
+            accent={deadCount > 0 ? 'warning' : 'amber'}
+            detail={
+              <span className={styles.breakdown}>
+                <span className={styles.bpLive}><StatusDot variant="live" /> {liveCount} live</span>
+                <span className={styles.bpStale}><StatusDot variant="stale" /> {staleCount} stale</span>
+                <span className={styles.bpDead}><StatusDot variant="dead" /> {deadCount} dead</span>
+              </span>
+            }
+          />
+          <StatCard
+            label="Applications"
+            value={String(groups.length)}
+            accent="running"
+            detail={
+              <span className={styles.breakdown}>
+                <span className={styles.bpLive}><StatusDot variant="live" /> {groups.filter((g) => g.deadCount === 0 && g.staleCount === 0).length} healthy</span>
+                <span className={styles.bpStale}><StatusDot variant="stale" /> {groups.filter((g) => g.staleCount > 0 && g.deadCount === 0).length} degraded</span>
+                <span className={styles.bpDead}><StatusDot variant="dead" /> {groups.filter((g) => g.deadCount > 0).length} critical</span>
+              </span>
+            }
+          />
+          <StatCard
+            label="Active Routes"
+            value={<span className={styles[totalActiveRoutes === 0 ? 'routesError' : totalActiveRoutes < totalRoutes ? 'routesWarning' : 'routesSuccess']}>{totalActiveRoutes}/{totalRoutes}</span>}
+            accent={totalActiveRoutes === 0 ? 'error' : totalActiveRoutes < totalRoutes ? 'warning' : 'success'}
+            detail={totalActiveRoutes < totalRoutes ? `${totalRoutes - totalActiveRoutes} suspended` : 'all routes active'}
+          />
+          <StatCard
+            label="Total TPS"
+            value={totalTps.toFixed(1)}
+            accent="amber"
+            detail="msg/s"
+            trend="up"
+            trendValue="4.2%"
+          />
+          <StatCard
+            label="Dead"
+            value={String(deadCount)}
+            accent={deadCount > 0 ? 'error' : 'success'}
+            detail={deadCount > 0 ? 'requires attention' : 'all healthy'}
+          />
         </div>
 
         {/* Scope breadcrumb trail */}
         {scope.level !== 'all' && (
           <div className={styles.scopeTrail}>
             <Link to="/agents" className={styles.scopeLink}>All Agents</Link>
-            {scope.level === 'instance' && (
-              <>
-                <span className={styles.scopeSep}>&#9656;</span>
-                <Link to={`/agents/${scope.appId}`} className={styles.scopeLink}>{scope.appId}</Link>
-              </>
-            )}
             <span className={styles.scopeSep}>&#9656;</span>
-            <span className={styles.scopeCurrent}>
-              {scope.level === 'app' ? scope.appId : scope.instanceId}
-            </span>
+            <span className={styles.scopeCurrent}>{scope.appId}</span>
           </div>
         )}
 
         {/* Section header */}
         <div className={styles.sectionHeaderRow}>
           <span className={styles.sectionTitle}>
-            {scope.level === 'all' ? 'Agents' : scope.level === 'app' ? scope.appId : scope.instanceId}
+            {scope.level === 'all' ? 'Agents' : scope.appId}
           </span>
           <Badge
             label={`${liveCount}/${totalInstances} live`}
@@ -240,78 +381,48 @@ export function AgentHealth() {
                 </thead>
                 <tbody>
                   {group.instances.map((inst) => (
-                    <>
-                      <tr
-                        key={inst.id}
-                        className={[
-                          styles.instanceRow,
-                          scope.level === 'instance' && scope.instanceId === inst.id ? styles.instanceRowActive : '',
-                        ].filter(Boolean).join(' ')}
-                        onClick={() => navigate(`/agents/${inst.appId}/${inst.id}`)}
-                      >
-                        <td className={styles.tdStatus}>
-                          <StatusDot variant={inst.status === 'live' ? 'live' : inst.status === 'stale' ? 'stale' : 'dead'} />
-                        </td>
-                        <td>
-                          <MonoText size="sm" className={styles.instanceName}>{inst.name}</MonoText>
-                        </td>
-                        <td>
-                          <Badge
-                            label={inst.status.toUpperCase()}
-                            color={inst.status === 'live' ? 'success' : inst.status === 'stale' ? 'warning' : 'error'}
-                            variant="filled"
-                          />
-                        </td>
-                        <td>
-                          <MonoText size="xs" className={styles.instanceMeta}>{inst.uptime}</MonoText>
-                        </td>
-                        <td>
-                          <MonoText size="xs" className={styles.instanceMeta}>{inst.tps.toFixed(1)}/s</MonoText>
-                        </td>
-                        <td>
-                          <MonoText size="xs" className={inst.errorRate ? styles.instanceError : styles.instanceMeta}>
-                            {inst.errorRate ?? '0 err/h'}
-                          </MonoText>
-                        </td>
-                        <td>
-                          <MonoText size="xs" className={
-                            inst.status === 'dead' ? styles.instanceHeartbeatDead :
-                            inst.status === 'stale' ? styles.instanceHeartbeatStale :
-                            styles.instanceMeta
-                          }>
-                            {inst.lastSeen}
-                          </MonoText>
-                        </td>
-                      </tr>
-
-                      {/* Expanded charts for single instance */}
-                      {singleInstance?.id === inst.id && trendData && (
-                        <tr key={`${inst.id}-charts`} className={styles.chartRow}>
-                          <td colSpan={7}>
-                            <div className={styles.instanceCharts}>
-                              <div className={styles.chartPanel}>
-                                <div className={styles.chartTitle}>Throughput (msg/s)</div>
-                                <LineChart
-                                  series={[{ label: 'tps', data: trendData.throughput }]}
-                                  height={160}
-                                  width={480}
-                                  yLabel="msg/s"
-                                />
-                              </div>
-                              <div className={styles.chartPanel}>
-                                <div className={styles.chartTitle}>Error Rate (err/h)</div>
-                                <LineChart
-                                  series={[{ label: 'errors', data: trendData.errorRate, color: 'var(--error)' }]}
-                                  height={160}
-                                  width={480}
-                                  yLabel="err/h"
-                                />
-                              </div>
-                            </div>
-                          </td>
-                        </tr>
-                      )}
-                    </>
+                    <tr
+                      key={inst.id}
+                      className={[
+                        styles.instanceRow,
+                        selectedInstance?.id === inst.id && panelOpen ? styles.instanceRowActive : '',
+                      ].filter(Boolean).join(' ')}
+                      onClick={() => handleInstanceClick(inst)}
+                    >
+                      <td className={styles.tdStatus}>
+                        <StatusDot variant={inst.status === 'live' ? 'live' : inst.status === 'stale' ? 'stale' : 'dead'} />
+                      </td>
+                      <td>
+                        <MonoText size="sm" className={styles.instanceName}>{inst.name}</MonoText>
+                      </td>
+                      <td>
+                        <Badge
+                          label={inst.status.toUpperCase()}
+                          color={inst.status === 'live' ? 'success' : inst.status === 'stale' ? 'warning' : 'error'}
+                          variant="filled"
+                        />
+                      </td>
+                      <td>
+                        <MonoText size="xs" className={styles.instanceMeta}>{inst.uptime}</MonoText>
+                      </td>
+                      <td>
+                        <MonoText size="xs" className={styles.instanceMeta}>{inst.tps.toFixed(1)}/s</MonoText>
+                      </td>
+                      <td>
+                        <MonoText size="xs" className={inst.errorRate ? styles.instanceError : styles.instanceMeta}>
+                          {inst.errorRate ?? '0 err/h'}
+                        </MonoText>
+                      </td>
+                      <td>
+                        <MonoText size="xs" className={
+                          inst.status === 'dead' ? styles.instanceHeartbeatDead :
+                          inst.status === 'stale' ? styles.instanceHeartbeatStale :
+                          styles.instanceMeta
+                        }>
+                          {inst.lastSeen}
+                        </MonoText>
+                      </td>
+                    </tr>
                   ))}
                 </tbody>
               </table>