refactor: centralize configuration management with type-safe schema

Major changes:
- Add dataclass-based configuration schema with validation (config/schema.py)
- Create centralized config loader and default values (config/defaults.py, config/loader.py)
- Remove duplicate database_config.py, merge into unified structure
- Consolidate browser settings into ERP config
- Add batch_size parameter support to extractor

Bug fixes:
- Fix settings save error by updating config paths (browser.* → erp.*)
- Fix batch_size not being applied in data extraction

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

utils/离散备料计划维护数据提取.py

@@ -14,7 +14,7 @@ from typing import Callable, Optional
 class DiscreteMaterialPlanExtractor:
     """离散备料计划维护数据提取器"""
 
-    def __init__(self, username, password, headless=False, verbose=True, progress_callback=None):
+    def __init__(self, username, password, headless=False, verbose=True, batch_size=100):
         """
         初始化提取器
 
@@ -23,13 +23,14 @@ class DiscreteMaterialPlanExtractor:
             password: 登录密码
             headless: 是否无头模式运行
             verbose: 是否打印详细日志
-            progress_callback: 进度回调函数，接收 ProgressInfo 对象
+            batch_size: 批次大小
         """
         self.username = username
         self.password = password
         self.headless = headless
         self.verbose = verbose
-        self.progress_callback = progress_callback
+        self.batch_size = batch_size
+        self.progress_callback = None
         self.converter = ExcelConverter(verbose=verbose)
 
     def _print(self, *args, **kwargs):
@@ -302,9 +303,9 @@ class DiscreteMaterialPlanExtractor:
                 # 按批次下载
                 downloaded_files = []
                 # 计算总批次数
-                total_batches = sum(1 for _ in self.group_order_ids(order_ids, 100))
+                total_batches = sum(1 for _ in self.group_order_ids(order_ids, self.batch_size))
 
-                for batch_index, order_ids_batch in enumerate(self.group_order_ids(order_ids, 100)):
+                for batch_index, order_ids_batch in enumerate(self.group_order_ids(order_ids, self.batch_size)):
                     self._print(f"\n=== 开始处理第 {batch_index + 1} 批，共 {len(order_ids_batch)} 个订单号 ===")
 
                     # 报告开始下载批次