Add bridge lane health API and config-ready lane UI for Tier A Week 3.

Probe LINK balances on CCIP bridge contracts, expose proof-transfer metadata on bridge status, and render funded/unfunded lane health on /bridge with extended smoke coverage.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/explorer/BridgeLaneHealthPanel.tsx

@@ -0,0 +1,107 @@
+'use client'
+
+import Link from 'next/link'
+import { Card } from '@/libs/frontend-ui-primitives'
+import EntityBadge from '@/components/common/EntityBadge'
+import type { MissionControlBridgeLane, MissionControlBridgeLaneHealth } from '@/services/api/missionControl'
+
+function laneTone(status?: string | null): 'success' | 'warning' | 'info' | 'neutral' {
+  switch (String(status || '').toLowerCase()) {
+    case 'funded':
+    case 'proof-recorded':
+      return 'success'
+    case 'degraded':
+    case 'proof-pending':
+      return 'warning'
+    case 'unfunded':
+      return 'warning'
+    default:
+      return 'neutral'
+  }
+}
+
+function formatLinkBalance(wei?: string | null): string {
+  if (!wei) return 'Unknown'
+  try {
+    const value = BigInt(wei)
+    const whole = value / 10n ** 18n
+    const fractional = (value % 10n ** 18n).toString().padStart(18, '0').slice(0, 4).replace(/0+$/, '')
+    return fractional ? `${whole}.${fractional} LINK` : `${whole} LINK`
+  } catch {
+    return wei
+  }
+}
+
+export default function BridgeLaneHealthPanel({
+  laneHealth,
+  className = '',
+}: {
+  laneHealth?: MissionControlBridgeLaneHealth | null
+  className?: string
+}) {
+  const lanes = laneHealth?.lanes || []
+  if (lanes.length === 0) return null
+
+  const normalizedClassName = className ? ` ${className}` : ''
+
+  return (
+    <Card title="Config-ready lane health" className={`mb-8${normalizedClassName}`}>
+      <p className="mb-4 text-sm text-gray-600 dark:text-gray-400">
+        LINK balances are read from each remote CCIP bridge contract. Proof-transfer status comes from operator-recorded CCIP message hashes when available.
+      </p>
+      <p className="mb-4 text-sm text-gray-600 dark:text-gray-400">
+        Operator runbook: fund LINK with{' '}
+        <code className="rounded bg-gray-100 px-1.5 py-0.5 text-xs dark:bg-gray-900">fund-ccip-bridges-with-link.sh</code>
+        {' '}· lane probe{' '}
+        <code className="rounded bg-gray-100 px-1.5 py-0.5 text-xs dark:bg-gray-900">probe-bridge-lane-link-balances.sh</code>
+        {' '}· routing reference{' '}
+        <Link href="/docs/public-api-access" className="text-primary-600 hover:underline">
+          public API access
+        </Link>
+      </p>
+      <div className="overflow-x-auto">
+        <table className="min-w-full text-sm">
+          <thead>
+            <tr className="border-b border-gray-200 text-left text-xs uppercase tracking-wide text-gray-500 dark:border-gray-700 dark:text-gray-400">
+              <th className="py-2 pr-4">Lane</th>
+              <th className="py-2 pr-4">Overall</th>
+              <th className="py-2 pr-4">Proof</th>
+              <th className="py-2 pr-4">WETH9 bridge</th>
+              <th className="py-2 pr-4">WETH10 bridge</th>
+            </tr>
+          </thead>
+          <tbody>
+            {lanes.map((lane: MissionControlBridgeLane) => (
+              <tr key={lane.key} className="border-b border-gray-100 align-top last:border-0 dark:border-gray-800">
+                <td className="py-3 pr-4">
+                  <div className="font-medium text-gray-900 dark:text-white">{lane.chain_name || lane.key}</div>
+                  <div className="mt-1 text-xs text-gray-500 dark:text-gray-400">chain {lane.chain_id ?? '?'}</div>
+                </td>
+                <td className="py-3 pr-4">
+                  <EntityBadge label={lane.status || 'unknown'} tone={laneTone(lane.status)} />
+                </td>
+                <td className="py-3 pr-4">
+                  <EntityBadge label={lane.proof_status || 'proof-pending'} tone={laneTone(lane.proof_status)} />
+                </td>
+                <td className="py-3 pr-4">
+                  <div className="font-mono text-xs text-gray-700 dark:text-gray-300">{lane.weth9?.bridge || '—'}</div>
+                  <div className="mt-1 flex flex-wrap items-center gap-2">
+                    <EntityBadge label={lane.weth9?.status || 'unknown'} tone={laneTone(lane.weth9?.status)} className="px-2 py-0.5 text-[11px]" />
+                    <span className="text-xs text-gray-600 dark:text-gray-400">{formatLinkBalance(lane.weth9?.link_balance_wei)}</span>
+                  </div>
+                </td>
+                <td className="py-3 pr-4">
+                  <div className="font-mono text-xs text-gray-700 dark:text-gray-300">{lane.weth10?.bridge || '—'}</div>
+                  <div className="mt-1 flex flex-wrap items-center gap-2">
+                    <EntityBadge label={lane.weth10?.status || 'unknown'} tone={laneTone(lane.weth10?.status)} className="px-2 py-0.5 text-[11px]" />
+                    <span className="text-xs text-gray-600 dark:text-gray-400">{formatLinkBalance(lane.weth10?.link_balance_wei)}</span>
+                  </div>
+                </td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      </div>
+    </Card>
+  )
+}

frontend/src/components/explorer/BridgeMonitoringPage.tsx

@@ -20,6 +20,7 @@ import { resolveEffectiveFreshness } from '@/utils/explorerFreshness'
 import { bridgeRoutesApi, normalizeBridgeRouteEntries, type BridgeRoutesResponse } from '@/services/api/bridgeRoutes'
 import { createVisibilityAwarePoller } from '@/utils/visibilityRefresh'
 import { HOME_DASHBOARD_REFRESH_MS } from '@/utils/featuredTokens'
+import BridgeLaneHealthPanel from '@/components/explorer/BridgeLaneHealthPanel'
 import OperationsSurfaceNav from './OperationsSurfaceNav'
 import OperationsActionGrid from './OperationsActionGrid'
 
@@ -460,6 +461,8 @@ export default function BridgeMonitoringPage({
         ))}
       </div>
 
+      <BridgeLaneHealthPanel laneHealth={bridgeStatus?.data?.bridge_lanes} />
+
       {routeEntries.length > 0 ? (
         <Card title="CCIP route catalog" className="mb-8">
           <p className="mb-4 text-sm text-gray-600 dark:text-gray-400">