fix: stop auto-creating Unknown leads on caller resolve

Return empty IDs for unrecognized numbers instead of creating lead+patient.
Per PRD: 'System will not identify the patient — no summary shown.'
Records are created when agent books appointment or logs enquiry.

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

src/caller/caller-resolution.service.ts

@@ -23,7 +23,12 @@ export class CallerResolutionService {
         private readonly cache: SessionService,
     ) {}
 
-    // Resolve a caller by phone number. Always returns a paired lead + patient.
+    // Resolve a caller by phone number.
+    // Looks up existing lead + patient by phone. If neither exists, returns
+    // isNew: true with no IDs — records are NOT created automatically.
+    // Record creation happens when the agent explicitly books an appointment
+    // or logs an enquiry (per PRD: "System will not identify the patient —
+    // no summary shown" for unregistered numbers).
     async resolve(phone: string, auth: string): Promise<ResolvedCaller> {
         const normalized = phone.replace(/\D/g, '').slice(-10);
         if (normalized.length < 10) {
@@ -85,13 +90,12 @@ export class CallerResolutionService {
                 isNew: false,
             };
         } else {
-            // Neither exists — create both
-            const newPatient = await this.createPatient('', '', normalized, auth);
-            const newLead = await this.createLead('', '', normalized, newPatient.id, auth);
-            this.logger.log(`[RESOLVE] Created new lead ${newLead.id} + patient ${newPatient.id} for ${normalized}`);
+            // Neither exists — return empty result, don't create records.
+            // Agent will create records when they book an appointment or log an enquiry.
+            this.logger.log(`[RESOLVE] No existing records for ${normalized} — returning unresolved`);
             result = {
-                leadId: newLead.id,
-                patientId: newPatient.id,
+                leadId: '',
+                patientId: '',
                 firstName: '',
                 lastName: '',
                 phone: normalized,