docs: update LLM model configs API documentation for group endpoints

- Add note clarifying that GET endpoints for groups return the same structure as user endpoints
- Document LLMModelConfigListResponse schema with default configuration selection logic
- Add comprehensive example for GET group configurations endpoint
- Update endpoint numbering to accommodate new group endpoints
- Ensure consistency between user and group API documentation

gns3server/schemas/controller/llm_model_configs.py

@@ -126,3 +126,11 @@ class LLMModelConfigInheritedResponse(BaseModel):
     configs: list[LLMModelConfigWithSource]
     default_config: Optional[LLMModelConfigWithSource] = None
     total: int
+
+
+class LLMModelConfigListResponse(BaseModel):
+    """Response containing a list of model configurations with default."""
+
+    configs: list[LLMModelConfigResponse]
+    default_config: Optional[LLMModelConfigResponse] = None
+    total: int