feat: implement IPC handlers, database services and Extractor UI

- Add SqlServerService and MySqlService for database persistence
- Implement IPC handlers for file, extractor, cleaner, and database operations
- Define IPC API types and update preload script
- Create ExtractorPage UI with OrderNumberInput component
- Add unit and integration tests for MySQL and SQL Server
- Update vitest config with path aliases

src/main/ipc/index.ts

@@ -0,0 +1,19 @@
+/**
+ * IPC Handler registration
+ * Centralized registration for all IPC handlers
+ */
+
+import { registerFileHandlers } from './file-handler'
+import { registerExtractorHandlers } from './extractor-handler'
+import { registerCleanerHandlers } from './cleaner-handler'
+import { registerDatabaseHandlers } from './database-handler'
+
+/**
+ * Register all IPC handlers
+ */
+export function registerIpcHandlers(): void {
+  registerFileHandlers()
+  registerExtractorHandlers()
+  registerCleanerHandlers()
+  registerDatabaseHandlers()
+}