feat(api): add pull request and wiki API endpoints with OpenAPI generator

- Add gen_openapi binary for generating OpenAPI specification
- Implement comprehensive pull request API endpoints including core operations
- Add pull request reviews, check runs, labels, assignees, and events APIs
- Include pull request status and merge strategy management endpoints
- Add wiki page CRUD operations with revision history and comparison
- Update OpenAPI documentation with Pull Requests and Wiki tags
- Modify workspace find function visibility for external access
- Integrate new API modules into main OpenAPI router configuration

service/workspace/core.rs

@@ -500,7 +500,7 @@ impl WorkspaceService {
         }
     }
 
-    pub(crate) async fn find_workspace_by_id(
+    pub async fn find_workspace_by_id(
         &self,
         workspace_id: Uuid,
     ) -> Result<Workspace, AppError> {