feat: add SQL Server database persistence for extracted material plan data

Add optional database persistence feature that automatically saves extracted
discrete material plan data to SQL Server. Users can enable this feature in
the settings tab.

Changes:
- Add enable_db_persistence flag to ExtractionConfig (default: disabled)
- Create DiscreteMaterialPlanDAO for database operations with REPLACE pattern
- Update progress tracking to include database persistence stage (90-100%)
- Add database persistence checkbox in settings UI
- Remove verbose logging checkbox from data extraction UI (config-only now)
- Update extraction workflow to save merged DataFrame to database

Progress weights adjusted:
- download: 65% -> 60%
- database: 10% (new stage)
- Other stages adjusted accordingly

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

gui/settings_tab.py

@@ -218,6 +218,12 @@ class SettingsTab(ttk.Frame):
             group, text="自动合并批次数据", variable=self.merge_batches_var
         ).grid(row=3, column=0, columnspan=2, sticky="w", pady=5)
 
+        # 数据库持久化
+        self.enable_db_persistence_var = tk.BooleanVar()
+        ttk.Checkbutton(
+            group, text="保存到数据库 (同时写入 SQL Server)", variable=self.enable_db_persistence_var
+        ).grid(row=4, column=0, columnspan=2, sticky="w", pady=5)
+
     def load_settings(self):
         """从配置加载设置到界面"""
         # ERP 设置
@@ -247,6 +253,7 @@ class SettingsTab(ttk.Frame):
         self.verbose_var.set(self.config.get("extraction.verbose", True))
         self.auto_convert_var.set(self.config.get("extraction.auto_convert", True))
         self.merge_batches_var.set(self.config.get("extraction.merge_batches", True))
+        self.enable_db_persistence_var.set(self.config.get("extraction.enable_db_persistence", False))
 
     def save_settings(self):
         """保存界面设置到配置"""
@@ -275,6 +282,7 @@ class SettingsTab(ttk.Frame):
         self.config.set("extraction.verbose", self.verbose_var.get())
         self.config.set("extraction.auto_convert", self.auto_convert_var.get())
         self.config.set("extraction.merge_batches", self.merge_batches_var.get())
+        self.config.set("extraction.enable_db_persistence", self.enable_db_persistence_var.get())
 
         # 保存到文件
         if self.config.save():