refactor(cortex): Epic 0 - Extract patient search hooks & components (E0.S1-S4)

DRY refactor: Extract reusable patient search logic from ZoekenBlock.

New files:
- lib/cortex/hooks/use-patient-search.ts (116 lines)
  Debounced patient search with abort controller
- lib/cortex/hooks/use-patient-selection.ts (98 lines)
  FHIR fetch + store update flow
- lib/fhir/patient-mapper.ts (109 lines)
  FHIR Patient to DB Patient mapping + utilities
- components/cortex/shared/patient-list-item.tsx (114 lines)
  Reusable patient list item with loading states

Refactored:
- ZoekenBlock: 349 -> 127 lines (-64%)

Documentation:
- docs/intent/patient-search/ux-analyse-patient-selectie.md
- docs/intent/patient-search/bouwplan-patient-selectie-v1.md

CLAUDE.md updated with Cortex architecture documentation.

Epic 0 complete: 4/4 stories (4 SP)

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/fhir/patient-mapper.ts

@@ -0,0 +1,158 @@
+/**
+ * FHIR Patient Mapper
+ *
+ * Maps FHIR Patient resources to database Patient format.
+ * Extracted from ZoekenBlock for DRY compliance.
+ *
+ * Epic: E0.S3 (Patient Selectie - Refactor)
+ */
+
+import type { Database } from '@/lib/supabase/database.types';
+
+export type Patient = Database['public']['Tables']['patients']['Row'];
+
+/**
+ * FHIR Patient resource structure (subset used in this app)
+ */
+export interface FhirPatient {
+  id: string;
+  resourceType?: 'Patient';
+  name?: Array<{
+    family?: string;
+    given?: string[];
+    prefix?: string[];
+    use?: string;
+  }>;
+  birthDate?: string;
+  gender?: string;
+  active?: boolean;
+  identifier?: Array<{
+    system?: string;
+    value?: string;
+  }>;
+  address?: Array<{
+    line?: string[];
+    city?: string;
+    postalCode?: string;
+    country?: string;
+  }>;
+  telecom?: Array<{
+    system?: string;
+    value?: string;
+  }>;
+}
+
+const GENDER_MAP: Record<string, Patient['gender']> = {
+  male: 'male',
+  female: 'female',
+  other: 'other',
+  unknown: 'unknown',
+};
+
+/**
+ * Maps a FHIR Patient resource to database Patient format
+ *
+ * @param fhir - FHIR Patient resource
+ * @returns Database Patient object
+ */
+export function mapFhirToDbPatient(fhir: FhirPatient): Patient {
+  const gender = GENDER_MAP[fhir.gender?.toLowerCase() || 'unknown'] || 'unknown';
+  const primaryName = fhir.name?.[0];
+  const primaryAddress = fhir.address?.[0];
+
+  // Extract identifiers
+  const bsn = fhir.identifier?.find(
+    (id) => id.system === 'http://fhir.nl/fhir/NamingSystem/bsn'
+  )?.value;
+
+  const clientNumber = fhir.identifier?.find(
+    (id) => id.system?.includes('client') || id.system?.includes('999.7.6')
+  )?.value;
+
+  // Extract telecom
+  const email = fhir.telecom?.find((t) => t.system === 'email')?.value;
+  const phone = fhir.telecom?.find((t) => t.system === 'phone')?.value;
+
+  return {
+    id: fhir.id,
+    name_family: primaryName?.family || '',
+    name_given: primaryName?.given || [],
+    name_prefix: primaryName?.prefix?.join(' ') || null,
+    name_use: primaryName?.use || null,
+    birth_date: fhir.birthDate || '',
+    gender,
+    active: fhir.active !== false,
+    identifier_bsn: bsn || null,
+    identifier_client_number: clientNumber || null,
+    // Address
+    address_line: primaryAddress?.line || null,
+    address_city: primaryAddress?.city || null,
+    address_postal_code: primaryAddress?.postalCode || null,
+    address_country: primaryAddress?.country || null,
+    // Telecom
+    telecom_email: email || null,
+    telecom_phone: phone || null,
+    // Null defaults for fields not in FHIR
+    status: null,
+    created_at: null,
+    updated_at: null,
+    emergency_contact_name: null,
+    emergency_contact_phone: null,
+    emergency_contact_relationship: null,
+    general_practitioner_name: null,
+    general_practitioner_agb: null,
+    insurance_company: null,
+    insurance_number: null,
+    is_john_doe: null,
+  };
+}
+
+/**
+ * Formats a patient's full name from database format
+ *
+ * @param patient - Database Patient object
+ * @returns Formatted full name
+ */
+export function formatPatientName(patient: Patient): string {
+  const given = patient.name_given?.[0] || '';
+  const family = patient.name_family || '';
+  return `${given} ${family}`.trim();
+}
+
+/**
+ * Calculates patient age from birth date
+ *
+ * @param birthDate - Birth date string (ISO format)
+ * @returns Age in years, or null if invalid
+ */
+export function calculatePatientAge(birthDate: string | null): number | null {
+  if (!birthDate) return null;
+
+  const birth = new Date(birthDate);
+  if (isNaN(birth.getTime())) return null;
+
+  const today = new Date();
+  let age = today.getFullYear() - birth.getFullYear();
+  const monthDiff = today.getMonth() - birth.getMonth();
+
+  if (monthDiff < 0 || (monthDiff === 0 && today.getDate() < birth.getDate())) {
+    age--;
+  }
+
+  return age;
+}
+
+/**
+ * Generates initials from patient name
+ *
+ * @param name - Full name string
+ * @returns 2-character initials
+ */
+export function getPatientInitials(name: string): string {
+  return name
+    .split(' ')
+    .map((n) => n[0])
+    .join('')
+    .slice(0, 2)
+    .toUpperCase();
+}