fix(06-03): remove sys.path manipulation from kb_workflow.py

- Remove unnecessary sys.path.insert for project root
- Update docstring to reference kb_workflow.pipeline
- Package imports work correctly without path manipulation

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

kb_workflow/kb_workflow.py

@@ -6,7 +6,7 @@ KB Workflow - Knowledge Base Workflow Orchestrator
 知识库工作流管道入口。
 
 此模块提供 process_command() 函数作为管道入口，
-内部使用 kb_pipeline 包实现完整的内容处理流程。
+内部使用 kb_workflow.pipeline 包实现完整的内容处理流程。
 
 使用方式:
     python kb_workflow.py process "https://www.bilibili.com/video/BVxxx"
@@ -37,11 +37,6 @@ def process_command(
     Returns:
         Dictionary with success status, content_dir, and results
     """
-    # Add project root to path for kb_pipeline imports
-    project_root = Path(__file__).parent.parent
-    if str(project_root) not in sys.path:
-        sys.path.insert(0, str(project_root))
-
     try:
         from kb_workflow.pipeline.config import get_settings
         from kb_workflow.pipeline.pipeline import Pipeline