fix: remove hardcoded Inbound_918041763265 campaign fallback

The default campaign name was hardcoded to 'Inbound_918041763265'.
After the Ozonetel campaigns were renamed (Inbound_918041763265 →
Global, Inbound_918041763400 → Ramaiah), agent login/dial would
break because the old name doesn't exist on Ozonetel anymore.

Campaign name now comes exclusively from the Agent entity's
campaignName field (per-agent) or the OZONETEL_CAMPAIGN_NAME env
var (per-workspace). No hardcoded fallback.

src/auth/agent-config.service.ts

@@ -29,7 +29,11 @@ export class AgentConfigService {
         return this.telephony.getConfig().sip.wsPort || '444';
     }
     private get defaultCampaignName(): string {
-        return this.telephony.getConfig().ozonetel.campaignName || 'Inbound_918041763265';
+        // No hardcoded fallback — each Agent entity's own campaignName
+        // field is the source of truth. Env var is the per-workspace
+        // default; if neither is set, the Ozonetel login will use
+        // whatever the agent's entity specifies.
+        return this.telephony.getConfig().ozonetel.campaignName || '';
     }
 
     async getByMemberId(memberId: string): Promise<AgentConfig | null> {