♻️ refactor: restructure MjLogsTable into modular component architecture

Refactor the monolithic MjLogsTable component (971 lines) into a modular,
maintainable architecture following the same pattern as LogsTable refactor.

## What Changed

### 🏗️ Architecture
- Split large single file into focused, single-responsibility components
- Introduced custom hook `useMjLogsData` for centralized state management
- Created dedicated column definitions file for better organization
- Implemented specialized modal components for Midjourney-specific features

### 📁 New Structure
```
web/src/components/table/mj-logs/
├── index.jsx                    # Main page component orchestrator
├── MjLogsTable.jsx             # Pure table rendering component
├── MjLogsActions.jsx           # Actions area (banner + compact mode)
├── MjLogsFilters.jsx           # Search form component
├── MjLogsColumnDefs.js         # Column definitions and renderers
└── modals/
    ├── ColumnSelectorModal.jsx # Column visibility settings
    └── ContentModal.jsx        # Content viewer (text + image preview)

web/src/hooks/mj-logs/
└── useMjLogsData.js            # Custom hook for state & logic
```

### 🎯 Key Improvements
- **Maintainability**: Clear separation of concerns, easier to understand
- **Reusability**: Modular components can be reused independently
- **Performance**: Optimized with `useMemo` for column rendering
- **Testing**: Single-responsibility components easier to test
- **Developer Experience**: Better code organization and readability

### 🎨 Midjourney-Specific Features Preserved
- All task type rendering with icons (IMAGINE, UPSCALE, VARIATION, etc.)
- Status rendering with appropriate colors and icons
- Image preview functionality for generated artwork
- Progress indicators for task completion
- Admin-only columns for channel and submission results
- Banner notification system for callback settings

### 🔧 Technical Details
- Centralized all business logic in `useMjLogsData` custom hook
- Extracted comprehensive column definitions with Lucide React icons
- Split complex UI into focused components (table, actions, filters, modals)
- Maintained responsive design patterns for mobile compatibility
- Preserved admin permission handling for restricted features

### 🐛 Fixes
- Improved component prop passing patterns
- Enhanced type safety through better state management
- Optimized rendering performance with proper memoization

## Breaking Changes
None - all existing imports and functionality preserved.

web/src/components/table/mj-logs/modals/ColumnSelectorModal.jsx

@@ -0,0 +1,92 @@
+import React from 'react';
+import { Modal, Button, Checkbox } from '@douyinfe/semi-ui';
+import { getMjLogsColumns } from '../MjLogsColumnDefs.js';
+
+const ColumnSelectorModal = ({
+  showColumnSelector,
+  setShowColumnSelector,
+  visibleColumns,
+  handleColumnVisibilityChange,
+  handleSelectAll,
+  initDefaultColumns,
+  COLUMN_KEYS,
+  isAdminUser,
+  copyText,
+  openContentModal,
+  openImageModal,
+  t,
+}) => {
+  // Get all columns for display in selector
+  const allColumns = getMjLogsColumns({
+    t,
+    COLUMN_KEYS,
+    copyText,
+    openContentModal,
+    openImageModal,
+    isAdminUser,
+  });
+
+  return (
+    <Modal
+      title={t('列设置')}
+      visible={showColumnSelector}
+      onCancel={() => setShowColumnSelector(false)}
+      footer={
+        <div className="flex justify-end">
+          <Button onClick={() => initDefaultColumns()}>
+            {t('重置')}
+          </Button>
+          <Button onClick={() => setShowColumnSelector(false)}>
+            {t('取消')}
+          </Button>
+          <Button onClick={() => setShowColumnSelector(false)}>
+            {t('确定')}
+          </Button>
+        </div>
+      }
+    >
+      <div style={{ marginBottom: 20 }}>
+        <Checkbox
+          checked={Object.values(visibleColumns).every((v) => v === true)}
+          indeterminate={
+            Object.values(visibleColumns).some((v) => v === true) &&
+            !Object.values(visibleColumns).every((v) => v === true)
+          }
+          onChange={(e) => handleSelectAll(e.target.checked)}
+        >
+          {t('全选')}
+        </Checkbox>
+      </div>
+      <div
+        className="flex flex-wrap max-h-96 overflow-y-auto rounded-lg p-4"
+        style={{ border: '1px solid var(--semi-color-border)' }}
+      >
+        {allColumns.map((column) => {
+          // Skip admin-only columns for non-admin users
+          if (
+            !isAdminUser &&
+            (column.key === COLUMN_KEYS.CHANNEL ||
+              column.key === COLUMN_KEYS.SUBMIT_RESULT)
+          ) {
+            return null;
+          }
+
+          return (
+            <div key={column.key} className="w-1/2 mb-4 pr-2">
+              <Checkbox
+                checked={!!visibleColumns[column.key]}
+                onChange={(e) =>
+                  handleColumnVisibilityChange(column.key, e.target.checked)
+                }
+              >
+                {column.title}
+              </Checkbox>
+            </div>
+          );
+        })}
+      </div>
+    </Modal>
+  );
+};
+
+export default ColumnSelectorModal; 

web/src/components/table/mj-logs/modals/ContentModal.jsx

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+import React from 'react';
+import { Modal, ImagePreview } from '@douyinfe/semi-ui';
+
+const ContentModal = ({
+  isModalOpen,
+  setIsModalOpen,
+  modalContent,
+  isModalOpenurl,
+  setIsModalOpenurl,
+  modalImageUrl,
+}) => {
+  return (
+    <>
+      {/* Text Content Modal */}
+      <Modal
+        visible={isModalOpen}
+        onOk={() => setIsModalOpen(false)}
+        onCancel={() => setIsModalOpen(false)}
+        closable={null}
+        bodyStyle={{ height: '400px', overflow: 'auto' }}
+        width={800}
+      >
+        <p style={{ whiteSpace: 'pre-line' }}>{modalContent}</p>
+      </Modal>
+
+      {/* Image Preview Modal */}
+      <ImagePreview
+        src={modalImageUrl}
+        visible={isModalOpenurl}
+        onVisibleChange={(visible) => setIsModalOpenurl(visible)}
+      />
+    </>
+  );
+};
+
+export default ContentModal;