feat: add AI recall calling — books existing patients for routine cleanings

Adds a new recall conversation flow (recall-graph.ts) triggered from the
Patient Connection "AI Call" button: offers an existing patient a routine
exam & cleaning, classifies their yes/no reply, then books directly onto
the schedule (Column A, 30-minute slots, real conflict checking against
office hours and existing appointments) instead of only capturing a
preference for staff to follow up on.

Also adds a "Voice call" label in the message thread to distinguish call
transcripts from SMS, and updates the Call Templates settings UI with an
editable recall greeting.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/Frontend/src/pages/patient-connection-page.tsx

@@ -112,7 +112,7 @@ export default function PatientConnectionPage() {
       to: string;
       patientId: number;
     }) => {
-      return apiRequest("POST", "/api/twilio/make-ai-call", { to, patientId });
+      return apiRequest("POST", "/api/twilio/make-ai-call", { to, patientId, purpose: "recall" });
     },
     onSuccess: () => {
       toast({