Add twilio softphone with integrated AI assistant

backend/src/voice/dto/call-event.dto.ts

@@ -0,0 +1,25 @@
+export interface CallEventDto {
+  callSid: string;
+  direction: 'inbound' | 'outbound';
+  fromNumber: string;
+  toNumber: string;
+  status: string;
+}
+
+export interface DtmfEventDto {
+  callSid: string;
+  digit: string;
+}
+
+export interface TranscriptEventDto {
+  callSid: string;
+  transcript: string;
+  isFinal: boolean;
+}
+
+export interface AiSuggestionDto {
+  callSid: string;
+  suggestion: string;
+  type: 'response' | 'action' | 'insight';
+  data?: any;
+}

backend/src/voice/dto/initiate-call.dto.ts

@@ -0,0 +1,10 @@
+import { IsString, IsNotEmpty, Matches } from 'class-validator';
+
+export class InitiateCallDto {
+  @IsString()
+  @IsNotEmpty()
+  @Matches(/^\+?[1-9]\d{1,14}$/, {
+    message: 'Invalid phone number format (use E.164 format)',
+  })
+  toNumber: string;
+}