feat: build ProblemsView with traffic light status system

- Create ProblemsView with two tables: Active Problems and Resolved Problems
- Traffic light indicators: 8px circles with text labels (green=Active/Resolved, amber=In Progress)
- Expandable rows showing full narrative and linked consultations
- Linked consultations navigate to Consultations view
- Proper semantic table markup with scope="col"
- Height animation for expand/collapse (200ms, respects reduced motion)
- Task 9 complete

src/components/PMRInterface.tsx

@@ -5,6 +5,7 @@ import { PatientBanner } from './PatientBanner'
 import { SummaryView } from './views/SummaryView'
 import { ConsultationsView } from './views/ConsultationsView'
 import { MedicationsView } from './views/MedicationsView'
+import { ProblemsView } from './views/ProblemsView'
 
 interface PMRInterfaceProps {
   children?: React.ReactNode
@@ -43,6 +44,8 @@ export function PMRInterface({ children }: PMRInterfaceProps) {
         return <ConsultationsView />
       case 'medications':
         return <MedicationsView />
+      case 'problems':
+        return <ProblemsView onNavigate={handleNavigate} />
       default:
         return (
           <div className="bg-white border border-gray-200 rounded p-6">

src/components/views/ProblemsView.tsx

@@ -0,0 +1,294 @@
+import { useState, useEffect, useRef } from 'react'
+import { ChevronDown, ChevronUp, ExternalLink } from 'lucide-react'
+import { problems } from '@/data/problems'
+import { consultations } from '@/data/consultations'
+import type { Problem, Consultation } from '@/types/pmr'
+
+interface ProblemsViewProps {
+  onNavigate?: (view: 'consultations', itemId?: string) => void
+}
+
+type ProblemStatus = 'Active' | 'In Progress' | 'Resolved'
+
+function TrafficLight({ status }: { status: ProblemStatus }) {
+  const colorMap: Record<ProblemStatus, { bg: string; label: string }> = {
+    Active: { bg: 'bg-green-500', label: 'Active' },
+    'In Progress': { bg: 'bg-amber-500', label: 'In Progress' },
+    Resolved: { bg: 'bg-green-500', label: 'Resolved' },
+  }
+
+  const { bg, label } = colorMap[status]
+
+  return (
+    <div className="flex items-center gap-2">
+      <span
+        className={`w-2 h-2 rounded-full ${bg}`}
+        aria-label={`Status: ${label}`}
+        role="img"
+      />
+      <span className="text-xs text-gray-600">{label}</span>
+    </div>
+  )
+}
+
+function ProblemRow({
+  problem,
+  isExpanded,
+  onToggle,
+  onNavigate,
+  showOutcome,
+}: {
+  problem: Problem
+  isExpanded: boolean
+  onToggle: () => void
+  onNavigate?: (view: 'consultations', itemId?: string) => void
+  showOutcome: boolean
+}) {
+  const contentRef = useRef<HTMLDivElement>(null)
+  const [contentHeight, setContentHeight] = useState<number | undefined>(undefined)
+  const prefersReducedMotion = useRef(
+    window.matchMedia('(prefers-reduced-motion: reduce)').matches
+  ).current
+
+  useEffect(() => {
+    if (contentRef.current) {
+      setContentHeight(contentRef.current.scrollHeight)
+    }
+  }, [isExpanded])
+
+  const linkedConsultations = (problem.linkedConsultations ?? [])
+    .map((id) => consultations.find((c) => c.id === id))
+    .filter((c): c is Consultation => c !== undefined)
+
+  const handleLinkedClick = (consultationId: string) => {
+    if (onNavigate) {
+      onNavigate('consultations', consultationId)
+    }
+  }
+
+  return (
+    <>
+      <tr
+        className={`cursor-pointer hover:bg-blue-50 transition-colors ${
+          isExpanded ? 'bg-blue-50' : ''
+        }`}
+        onClick={onToggle}
+        aria-expanded={isExpanded}
+      >
+        <td className="border border-gray-200 px-3 py-2.5">
+          <TrafficLight status={problem.status} />
+        </td>
+        <td className="border border-gray-200 px-3 py-2.5">
+          <span className="font-mono text-xs text-gray-500">[{problem.code}]</span>
+        </td>
+        <td className="border border-gray-200 px-3 py-2.5">
+          <span className="text-sm text-gray-900">{problem.description}</span>
+        </td>
+        <td className="border border-gray-200 px-3 py-2.5">
+          <span className="font-mono text-xs text-gray-500">
+            {problem.resolved || problem.since}
+          </span>
+        </td>
+        {showOutcome && (
+          <td className="border border-gray-200 px-3 py-2.5">
+            {problem.outcome && (
+              <span className="text-sm text-gray-700">{problem.outcome}</span>
+            )}
+          </td>
+        )}
+        <td className="border border-gray-200 px-3 py-2.5 w-10">
+          <button
+            className="p-1 hover:bg-gray-100 rounded transition-colors"
+            aria-label={isExpanded ? 'Collapse' : 'Expand'}
+          >
+            {isExpanded ? (
+              <ChevronUp className="w-4 h-4 text-gray-400" />
+            ) : (
+              <ChevronDown className="w-4 h-4 text-gray-400" />
+            )}
+          </button>
+        </td>
+      </tr>
+      <tr>
+        <td colSpan={showOutcome ? 6 : 5} className="p-0 border border-gray-200">
+          <div
+            style={{
+              height: isExpanded ? contentHeight : 0,
+              overflow: 'hidden',
+              transition: prefersReducedMotion ? 'none' : 'height 200ms ease-out',
+            }}
+          >
+            <div ref={contentRef} className="bg-gray-50 p-4">
+              <div className="text-sm text-gray-700 leading-relaxed mb-4">
+                {problem.narrative}
+              </div>
+              {linkedConsultations.length > 0 && (
+                <div>
+                  <span className="text-xs font-semibold text-gray-400 uppercase tracking-wider">
+                    Linked Consultations:
+                  </span>
+                  <div className="mt-2 flex flex-wrap gap-2">
+                    {linkedConsultations.map((consultation) => (
+                      <button
+                        key={consultation.id}
+                        onClick={(e) => {
+                          e.stopPropagation()
+                          handleLinkedClick(consultation.id)
+                        }}
+                        className="inline-flex items-center gap-1 text-xs text-nhsblue hover:underline"
+                      >
+                        <ExternalLink className="w-3 h-3" />
+                        {consultation.organization} — {consultation.role}
+                      </button>
+                    ))}
+                  </div>
+                </div>
+              )}
+            </div>
+          </div>
+        </td>
+      </tr>
+    </>
+  )
+}
+
+export function ProblemsView({ onNavigate }: ProblemsViewProps) {
+  const [expandedId, setExpandedId] = useState<string | null>(null)
+
+  const activeProblems = problems.filter(
+    (p) => p.status === 'Active' || p.status === 'In Progress'
+  )
+  const resolvedProblems = problems.filter((p) => p.status === 'Resolved')
+
+  const handleToggle = (id: string) => {
+    setExpandedId(expandedId === id ? null : id)
+  }
+
+  return (
+    <div className="space-y-6">
+      <div className="bg-white border border-gray-200 rounded">
+        <div className="bg-gray-50 border-b border-gray-200 px-4 py-3">
+          <h2 className="font-inter font-semibold text-sm uppercase tracking-wider text-gray-500">
+            Active Problems
+          </h2>
+        </div>
+        <table className="w-full border-collapse">
+          <thead>
+            <tr className="bg-gray-50">
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-28"
+              >
+                Status
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-28"
+              >
+                Code
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400"
+              >
+                Problem
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-28"
+              >
+                Since
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-10"
+              >
+                <span className="sr-only">Expand</span>
+              </th>
+            </tr>
+          </thead>
+          <tbody>
+            {activeProblems.map((problem) => (
+              <ProblemRow
+                key={problem.id}
+                problem={problem}
+                isExpanded={expandedId === problem.id}
+                onToggle={() => handleToggle(problem.id)}
+                onNavigate={onNavigate}
+                showOutcome={false}
+              />
+            ))}
+          </tbody>
+        </table>
+        {activeProblems.length === 0 && (
+          <div className="p-4 text-sm text-gray-500 text-center">No active problems</div>
+        )}
+      </div>
+
+      <div className="bg-white border border-gray-200 rounded">
+        <div className="bg-gray-50 border-b border-gray-200 px-4 py-3">
+          <h2 className="font-inter font-semibold text-sm uppercase tracking-wider text-gray-500">
+            Resolved Problems
+          </h2>
+        </div>
+        <table className="w-full border-collapse">
+          <thead>
+            <tr className="bg-gray-50">
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-28"
+              >
+                Status
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-28"
+              >
+                Code
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400"
+              >
+                Problem
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-28"
+              >
+                Resolved
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400"
+              >
+                Outcome
+              </th>
+              <th
+                scope="col"
+                className="border border-gray-200 px-3 py-2 text-left font-inter font-semibold text-xs uppercase tracking-wider text-gray-400 w-10"
+              >
+                <span className="sr-only">Expand</span>
+              </th>
+            </tr>
+          </thead>
+          <tbody>
+            {resolvedProblems.map((problem) => (
+              <ProblemRow
+                key={problem.id}
+                problem={problem}
+                isExpanded={expandedId === problem.id}
+                onToggle={() => handleToggle(problem.id)}
+                onNavigate={onNavigate}
+                showOutcome={true}
+              />
+            ))}
+          </tbody>
+        </table>
+        {resolvedProblems.length === 0 && (
+          <div className="p-4 text-sm text-gray-500 text-center">No resolved problems</div>
+        )}
+      </div>
+    </div>
+  )
+}