feat: add Tkinter GUI application for ERP automation tools

Implement a comprehensive GUI application with the following features:
- Data Extraction tab: Extract material plan data from ERP system
- Material Validation tab: Validate material status and match deletions
- Data Query tab: Query database for production order information
- Settings tab: Manage ERP, database, browser, and path configurations

Key components:
- MainWindow: Tabbed interface with status bar
- ConfigManager: JSON-based configuration management
- LogText: Custom read-only text widget with colored logging
- FileSelector: Reusable file/directory selection component
- ProgressDialog: Modal progress dialog for long operations

Technical details:
- Thread-safe UI updates using root.after()
- Stdout capture for legacy script integration
- Event-based readonly mode allowing copy/select operations
- Custom widget composition to avoid Tkinter ScrolledText issues

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

gui/widgets/__init__.py

@@ -0,0 +1,10 @@
+"""
+GUI 自定义组件模块
+
+提供可复用的 UI 组件。
+"""
+
+from .file_selector import FileSelector
+from .log_text import LogText
+
+__all__ = ['FileSelector', 'LogText']