fix: clinicId on all appointment paths + startedAt on call records

- AI chat book_appointment tool: accepts optional clinicId
- Widget booking: passes clinicId from request
- LiveKit agent: passes clinicId from doctor context if available
- Dispose endpoint: sets startedAt/endedAt on outbound call records
  (computed from durationSec). Fixes null timestamps in call history.

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

src/ozonetel/ozonetel-agent.controller.ts

@@ -147,14 +147,21 @@ export class OzonetelAgentController {
         // only place that creates the call record for outbound dials.
         if (body.direction === 'OUTBOUND' && body.callerPhone) {
             try {
+                const durationSec = body.durationSec ?? 0;
+                const endedAt = new Date().toISOString();
+                const startedAt = durationSec > 0
+                    ? new Date(Date.now() - durationSec * 1000).toISOString()
+                    : endedAt;
                 const callData: Record<string, any> = {
                     name: `Outbound — ${body.callerPhone}`,
                     direction: 'OUTBOUND',
                     callStatus: 'COMPLETED',
                     callerNumber: { primaryPhoneNumber: `+91${body.callerPhone.replace(/^\+?91/, '')}` },
                     agentName: agentId,
-                    durationSec: body.durationSec ?? 0,
+                    durationSec,
                     disposition: body.disposition,
+                    startedAt,
+                    endedAt,
                 };
                 if (body.leadId) callData.leadId = body.leadId;