feat(diagnose): Master-detail layout en verbeterde ICD-10 combobox

Diagnose pagina:
- Master-detail layout (lijst links, formulier rechts)
- URL state voor selectie (?selected=uuid of ?selected=new)
- Inline CRUD zonder modals of navigatie
- Vereenvoudigde header (alleen actieve diagnoses teller)

ICD-10 Combobox:
- Vervangen cmdk/Command met simpele Popover + buttons (fix selectie bug)
- Direct typen in input veld (geen extra klik nodig)
- Auto-open dropdown bij focus/typen

Database:
- Fix FK constraint: conditions.encounter_id -> intakes (was encounters)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/epd/patients/[id]/diagnose/components/diagnosis-list-item.tsx

@@ -0,0 +1,64 @@
+'use client';
+
+import { Badge } from '@/components/ui/badge';
+import { cn } from '@/lib/utils';
+import type { DiagnosisWithIntake } from '../actions';
+
+interface DiagnosisListItemProps {
+  diagnosis: DiagnosisWithIntake;
+  isSelected: boolean;
+  onClick: () => void;
+}
+
+const STATUS_CONFIG: Record<string, { label: string; className: string }> = {
+  active: { label: 'Actief', className: 'bg-green-100 text-green-700 border-green-300' },
+  remission: { label: 'Remissie', className: 'bg-blue-100 text-blue-700 border-blue-300' },
+  resolved: { label: 'Opgelost', className: 'bg-slate-100 text-slate-700 border-slate-300' },
+  inactive: { label: 'Inactief', className: 'bg-amber-100 text-amber-700 border-amber-300' },
+};
+
+export function DiagnosisListItem({ diagnosis, isSelected, onClick }: DiagnosisListItemProps) {
+  const code = diagnosis.code_code || '';
+  const description = diagnosis.code_display || '';
+  const status = diagnosis.clinical_status || 'active';
+  const isPrimary = diagnosis.category === 'primary-diagnosis';
+  const statusConfig = STATUS_CONFIG[status] || STATUS_CONFIG.active;
+
+  return (
+    <button
+      type="button"
+      onClick={onClick}
+      className={cn(
+        'w-full text-left p-3 rounded-lg border transition-all',
+        'hover:border-teal-300 hover:bg-teal-50/50',
+        isSelected
+          ? 'border-teal-500 bg-teal-50 ring-1 ring-teal-500'
+          : 'border-slate-200 bg-white'
+      )}
+    >
+      <div className="flex items-start justify-between gap-2">
+        <div className="min-w-0 flex-1">
+          <div className="font-medium text-slate-900 truncate">
+            <span className="font-mono text-sm">{code}</span>
+            {description && (
+              <span className="ml-1.5 text-slate-700 font-normal">{description}</span>
+            )}
+          </div>
+          <div className="flex items-center gap-2 mt-1">
+            <Badge
+              variant="outline"
+              className={cn('text-xs', statusConfig.className)}
+            >
+              {statusConfig.label}
+            </Badge>
+            {isPrimary && (
+              <Badge className="bg-green-600 text-white text-xs hover:bg-green-600">
+                HOOFD
+              </Badge>
+            )}
+          </div>
+        </div>
+      </div>
+    </button>
+  );
+}