feat: 完成账号目录slug工具

- 新增 app/config.py，生成稳定账号 slug 并创建 user-data-dir

- db 账号创建复用统一 slug 规则

- 新增 config 单元测试覆盖 slug 和目录创建

- 更新任务看板、API 合约、当前状态和进度记录

app/db.py

@@ -2,10 +2,8 @@
 
 from __future__ import annotations
 
-import hashlib
 import json
 import os
-import re
 import sqlite3
 import uuid
 from contextlib import contextmanager
@@ -14,6 +12,7 @@ from datetime import datetime
 from typing import Iterable, Optional
 
 from . import appconfig
+from .config import make_slug
 
 
 DEFAULT_BUSY_TIMEOUT_MS = 5000
@@ -220,12 +219,6 @@ def _validate_fields(fields, allowed):
         raise DbError(f"不支持更新字段: {', '.join(unknown)}")
 
 
-def _slug_from_alias(alias: str) -> str:
-    base = re.sub(r"[^a-z0-9_]+", "_", alias.lower()).strip("_")
-    suffix = hashlib.sha1(alias.encode("utf-8")).hexdigest()[:8]
-    return f"{base}_{suffix}" if base else f"account_{suffix}"
-
-
 def _row_key(batch_id, source_file_abs, source_sheet, source_row) -> str:
     return f"{batch_id}:{source_file_abs}:{source_sheet}:{source_row}"
 
@@ -330,7 +323,7 @@ def add_account(
     path=None,
     conn=None,
 ):
-    slug = slug or _slug_from_alias(alias)
+    slug = slug or make_slug(alias)
     user_data_dir = user_data_dir or os.path.join("chrome_user_data_dir", slug)
     now = _now()
     with _connection(conn, path) as database: