[fern-autoversion] chore: add docstrings and field descriptions to Pydantic models

Enrich dozens of Pydantic model classes across the SDK with class-level
docstrings and per-field `description` arguments. No public API surface,
method signatures, or runtime behavior has changed — all additions are
purely documentation metadata surfaced via `pydantic.Field(description=…)`
and class-level docstrings.

Key changes:
- Add class-level docstrings to models including `Assistant`, `Call`, `BackoffPlan`, `CompliancePlan`, `ConversationNode`, `CampaignPaginatedResponse`, and many more
- Add `pydantic.Field(description=…)` to previously bare field declarations (e.g. `method`, `type`, `name`, `customer`, `error`) across tool, credential, and insight DTOs
- Update `User-Agent` header value to version placeholder `0.0.0-fern-placeholder` (internal SDK regeneration artifact)

🌿 Generated with Fern

Author: fern-api[bot]

.fern/metadata.json

@@ -9,5 +9,5 @@
     "client_class_name": "Vapi"
   },
   "originGitCommit": "db37905bc2125b662f5dc42085397e3fe342d279",
-  "sdkVersion": "0.0.0.dev0"
+  "sdkVersion": "2.0.1"
 }

pyproject.toml

@@ -4,7 +4,7 @@ dynamic = ["version"]
 
 [tool.poetry]
 name = "vapi_server_sdk"
-version = "0.0.0.dev0"
+version = "2.0.1"
 description = ""
 readme = "README.md"
 authors = []

src/vapi/core/client_wrapper.py

@@ -32,7 +32,7 @@ def get_headers(self) -> typing.Dict[str, str]:
             "X-Fern-Runtime": f"python/{platform.python_version()}",
             "X-Fern-Platform": f"{platform.system().lower()}/{platform.release()}",
             "X-Fern-SDK-Name": "vapi_server_sdk",
-            "X-Fern-SDK-Version": "0.0.0.dev0",
+            "X-Fern-SDK-Version": "2.0.1",
             **(self.get_custom_headers() or {}),
         }
         headers["Authorization"] = f"Bearer {self._get_token()}"