docs: clarify Python module responsibilities

Rewrite the module-level descriptions for all 28 Python files and remove the obsolete integration note from grok_register_ttk.py. Verified on Python 3.9 and Python 3.12.

registration_flow.py

@@ -1,4 +1,4 @@
-"""Shared registration workflow used by both GUI and CLI adapters."""
+"""编排 GUI 与 CLI 共用的单账号注册和批量执行流程。"""
 from dataclasses import dataclass, field
 from typing import Any, Callable, Dict, Optional, Tuple