♻️ 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/MjLogsActions.jsx

@@ -0,0 +1,47 @@
+import React from 'react';
+import { Button, Skeleton, Typography } from '@douyinfe/semi-ui';
+import { IconEyeOpened } from '@douyinfe/semi-icons';
+
+const { Text } = Typography;
+
+const MjLogsActions = ({
+  loading,
+  showBanner,
+  isAdminUser,
+  compactMode,
+  setCompactMode,
+  t,
+}) => {
+  return (
+    <div className="flex flex-col md:flex-row justify-between items-start md:items-center gap-2 w-full">
+      <div className="flex items-center text-orange-500 mb-2 md:mb-0">
+        <IconEyeOpened className="mr-2" />
+        {loading ? (
+          <Skeleton.Title
+            style={{
+              width: 300,
+              marginBottom: 0,
+              marginTop: 0
+            }}
+          />
+        ) : (
+          <Text>
+            {isAdminUser && showBanner
+              ? t('当前未开启Midjourney回调，部分项目可能无法获得绘图结果，可在运营设置中开启。')
+              : t('Midjourney 任务记录')}
+          </Text>
+        )}
+      </div>
+      <Button
+        type='tertiary'
+        className="w-full md:w-auto"
+        onClick={() => setCompactMode(!compactMode)}
+        size="small"
+      >
+        {compactMode ? t('自适应列表') : t('紧凑列表')}
+      </Button>
+    </div>
+  );
+};
+
+export default MjLogsActions;