feat: migrate ERP configuration from .env to per-user database storage

- Moved ERP credentials (URL, username, password) from environment variables to dbo_BIPUsers table
- Each user now has their own ERP configuration stored in the database
- Added UserErpConfigService for managing per-user ERP settings
- Updated cleaner and extractor handlers to fetch ERP config from database instead of .env
- Removed ERP fields from ConfigManager UI editable fields
- Added new IPC handlers and preload APIs for user ERP config management
- Includes migration script to transfer existing .env ERP settings to database
- Added migration guide documentation

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

src/preload/index.d.ts

@@ -235,6 +235,39 @@ export interface MaterialTypeAPI {
   }>
 }
 
+/**
+ * User ERP Configuration API
+ */
+export interface UserErpConfigAPI {
+  /**
+   * Get current user's ERP configuration
+   */
+  getCurrent: () => Promise<{
+    success: boolean
+    config?: { url: string; username: string; password: string }
+    error?: string
+  }>
+  /**
+   * Update current user's ERP configuration
+   */
+  update: (config: { url: string; username: string; password: string }) => Promise<{
+    success: boolean
+    config?: { url: string; username: string; password: string }
+    error?: string
+  }>
+  /**
+   * Test ERP connection with provided credentials
+   */
+  testConnection: (config: { url: string; username: string; password: string }) => Promise<{
+    success: boolean
+    message?: string
+  }>
+  /**
+   * Get all users' ERP configurations (admin only)
+   */
+  getAll: () => Promise<Array<{ username: string; erpUrl: string; erpUsername: string }>>
+}
+
 declare global {
   interface Window {
     electron: {
@@ -263,6 +296,7 @@ declare global {
       materials: MaterialsAPI
       settings: SettingsAPI
       materialType: MaterialTypeAPI
+      userErpConfig: UserErpConfigAPI
     }
     api: unknown
   }

src/preload/index.ts

@@ -137,6 +137,16 @@ const api = {
       ipcRenderer.invoke('materialType:delete', { materialName, managerName }),
     upsertBatch: (request: MaterialTypeBatchRequest) =>
       ipcRenderer.invoke('materialType:upsertBatch', request)
+  },
+
+  // User ERP Configuration service
+  userErpConfig: {
+    getCurrent: () => ipcRenderer.invoke('user-erp-config:getCurrent'),
+    update: (config: { url: string; username: string; password: string }) =>
+      ipcRenderer.invoke('user-erp-config:update', config),
+    testConnection: (config: { url: string; username: string; password: string }) =>
+      ipcRenderer.invoke('user-erp-config:testConnection', config),
+    getAll: () => ipcRenderer.invoke('user-erp-config:getAll')
   }
 } as const