[fern-autoversion] chore: add PHPDoc descriptions to types and request classes

Enrich dozens of PHP type and request classes with class-level PHPDoc
summaries and inline property descriptions. No public API signatures,
method names, or behavioral logic were changed — only documentation
comments were added or expanded.

Key changes:
- Add class-level PHPDoc blocks to types such as `Assistant`, `Call`, `Edge`, `CompliancePlan`, `BackoffPlan`, and many more
- Expand inline `@var` descriptions for properties like `firstMessageInterruptionsEnabled`, `compliancePlan`, `keypadInputPlan`, `baseDelaySeconds`, and `excludedStatusCodes`
- Improve property descriptions across insight DTOs (`BarInsight`, `LineInsight`, `PieInsight`, `TextInsight`) and credential DTOs (`CreateTwilioCredentialDto`, `CreateVonageCredentialDto`, etc.)

🌿 Generated with Fern

Author: fern-api[bot]

.fern/metadata.json

@@ -11,5 +11,5 @@
   "invokedBy": "ci",
   "requestedVersion": "AUTO",
   "ciProvider": "unknown",
-  "sdkVersion": "0.0.0-fern-placeholder"
+  "sdkVersion": "2.0.1"
 }

composer.json

@@ -1,6 +1,6 @@
 {
   "name": "vapi/vapi",
-  "version": "0.0.0-fern-placeholder",
+  "version": "2.0.1",
   "description": "Vapi PHP Library",
   "keywords": [
     "vapi",

src/VapiClient.php

@@ -131,8 +131,8 @@ public function __construct(
             'Authorization' => "Bearer $token",
             'X-Fern-Language' => 'PHP',
             'X-Fern-SDK-Name' => 'Vapi',
-            'X-Fern-SDK-Version' => '0.0.0-fern-placeholder',
-            'User-Agent' => 'vapi/vapi/0.0.0-fern-placeholder',
+            'X-Fern-SDK-Version' => '2.0.1',
+            'User-Agent' => 'vapi/vapi/2.0.1',
         ];
 
         $this->options = $options ?? [];