feat: add Exotel webhook controller and service for call event parsing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/exotel/exotel.controller.ts

@@ -0,0 +1,24 @@
+import { Controller, Post, Body, Logger, HttpCode } from '@nestjs/common';
+import { ExotelService } from './exotel.service';
+import type { ExotelWebhookPayload } from './exotel.types';
+
+@Controller('webhooks/exotel')
+export class ExotelController {
+    private readonly logger = new Logger(ExotelController.name);
+
+    constructor(private readonly exotelService: ExotelService) {}
+
+    @Post('call-status')
+    @HttpCode(200)
+    async handleCallStatus(@Body() payload: ExotelWebhookPayload) {
+        this.logger.log(`Received Exotel webhook: ${payload.event_details?.event_type}`);
+
+        const callEvent = this.exotelService.parseWebhook(payload);
+
+        // TODO: Forward to CallEventsService (Task 4)
+        // For now, just log
+        this.logger.log(`Call event: ${JSON.stringify(callEvent)}`);
+
+        return { status: 'received' };
+    }
+}