feat: allow editing manager field in cleaner table

- Add inline editing for manager column (Admin users can double-click to select from dropdown)
- Auto-assign current user as manager when User checks a material
- Defer database writes until 'Confirm Delete' button is clicked
- Add updateManager IPC handler and DAO method
- Update preload API with updateManager method

src/preload/index.d.ts

@@ -150,6 +150,15 @@ export interface MaterialsAPI {
    * Get statistics
    */
   getStatistics: () => Promise<{ stats: unknown }>
+  /**
+   * Update manager for a single material
+   * @param materialCode - Material code
+   * @param managerName - New manager name
+   */
+  updateManager: (
+    materialCode: string,
+    managerName: string
+  ) => Promise<{ success: boolean; error?: string }>
 }
 
 /**

src/preload/index.ts

@@ -103,7 +103,9 @@ const api = {
     getByManager: (managerName: string) =>
       ipcRenderer.invoke('materials:getByManager', managerName),
     getAll: () => ipcRenderer.invoke('materials:getAll'),
-    getStatistics: () => ipcRenderer.invoke('materials:getStatistics')
+    getStatistics: () => ipcRenderer.invoke('materials:getStatistics'),
+    updateManager: (materialCode: string, managerName: string) =>
+      ipcRenderer.invoke('materials:updateManager', { materialCode, managerName })
   },
 
   // Settings service