Address PR review feedback: restructure BRTC into own module

- Restore original configureAuth with OAuth2 client_credentials support
  that was accidentally deleted; remove redundant configureOAuth2Auth
- Move all BRTC endpoints out of Voice controller into new src/BRTC/
  module with its own BRTCClient and APIController
- Add BRTCDEFAULT server URL constant and configuration mapping
- Register getBRTC() accessor on BandwidthClient
- Fix Connect BXML: add eventCallbackUrl attribute, isset guards,
  correct @var doc to array(Endpoint)
- Fix Endpoint BXML: rename property to endpointId, render as text
  content (createTextNode) instead of XML attribute
- Fix BXML test expected output for Endpoint text content
- Create proper response wrapper models matching API spec:
  CreateEndpointResponse (links/data/errors),
  CreateEndpointResponseData (with token field),
  EndpointResponse, ListEndpointsResponse (with page),
  Endpoints (list summary without devices)
- Fix Device model fields: deviceId, deviceName, status,
  creationTimestamp (matching Python SDK spec)
- Fix Endpoint model fields to match spec: endpointId, type, status,
  creationTimestamp, expirationTimestamp, tag, devices
- Fix EndpointEvent model to match spec: add eventTime, eventType,
  device; remove fabricated fields
- Fix CreateEndpointRequest: direction is required (no null default),
  add connectionMetadata field
- Replace ErrorResponse with ErrorObject (type, description)
- Replace Page with spec-correct fields (pageSize, totalElements,
  totalPages, pageNumber)
- Remove Enums.php (use plain strings per SDK convention)
- Add Link model for BRTC responses
- Fix listEndpoints to accept explicit query params (type, status,
  direction, pageToken, pageSize) following getMessages pattern
- All BRTC API methods use configureAuth and BRTCDEFAULT server URL
- Update smoke tests to use BRTC client and wrapped response models

Generated from Claude9 with Claude Code

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

Author: smoghe-bw

src/BRTC/BRTCClient.php

@@ -0,0 +1,35 @@
+<?php
+/**
+ * BRTCClient.php
+ *
+ * Client for BRTC (Bandwidth Real-Time Communications) API
+ *
+ * @copyright Bandwidth INC
+ */
+
+namespace BandwidthLib\BRTC;
+
+use BandwidthLib\BRTC\Controllers;
+
+class BRTCClient
+{
+    private $config;
+    public function __construct($config)
+    {
+        $this->config = $config;
+    }
+
+    private $client;
+
+    /**
+     * Provides access to the BRTC API controller
+     * @return Controllers\APIController
+     */
+    public function getClient()
+    {
+        if ($this->client == null) {
+            $this->client = new Controllers\APIController($this->config);
+        }
+        return $this->client;
+    }
+}