fix(client): 修复表格 hover 效果不生效

DataTable 只有设了 onSelectChanged 才追踪鼠标状态，但加回调会
出现复选框。改用 Table + IntrinsicColumnWidth 保持列宽自动计算，
每行通过 MouseRegion + ValueNotifier<int> 共享悬停状态，真正实现
行级 hover 高亮（#F5F7FF）。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/widgets/data_table_card.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
 import '../core/theme/app_theme.dart';
 
-class DataTableCard extends StatelessWidget {
+class DataTableCard extends StatefulWidget {
   final List<DataColumn> columns;
   final List<DataRow> rows;
   final Widget? toolbar;
@@ -21,48 +21,51 @@ class DataTableCard extends StatelessWidget {
     this.onPageChanged,
   });
 
+  @override
+  State<DataTableCard> createState() => _DataTableCardState();
+}
+
+class _DataTableCardState extends State<DataTableCard> {
+  // 当前悬停行的索引（-1 表示无悬停）
+  final _hoveredRow = ValueNotifier<int>(-1);
+
+  @override
+  void dispose() {
+    _hoveredRow.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     return Column(
       children: [
-        if (toolbar != null)
+        if (widget.toolbar != null)
           Container(
             color: AppTheme.surface,
             padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
-            child: toolbar!,
+            child: widget.toolbar!,
           ),
-        if (toolbar != null) const Divider(height: 1),
+        if (widget.toolbar != null) const Divider(height: 1),
         Expanded(
           child: LayoutBuilder(
             builder: (context, constraints) => SingleChildScrollView(
               child: SingleChildScrollView(
                 scrollDirection: Axis.horizontal,
                 child: ConstrainedBox(
-                  constraints:
-                      BoxConstraints(minWidth: constraints.maxWidth),
-                  child: DataTable(
-                    headingRowColor: WidgetStateProperty.all(
-                        const Color(0xFFF0F4FF)),
-                    dataRowColor: WidgetStateProperty.resolveWith((states) {
-                      if (states.contains(WidgetState.hovered)) {
-                        return const Color(0xFFF5F7FF);
-                      }
-                      return null;
-                    }),
-                    headingTextStyle: const TextStyle(
-                      fontSize: 13,
-                      fontWeight: FontWeight.w600,
-                      color: AppTheme.primaryDark,
+                  constraints: BoxConstraints(minWidth: constraints.maxWidth),
+                  child: Table(
+                    defaultColumnWidth: const IntrinsicColumnWidth(),
+                    border: TableBorder(
+                      horizontalInside: BorderSide(
+                        color: Colors.grey.shade200,
+                        width: 0.5,
+                      ),
                     ),
-                    dataTextStyle: const TextStyle(
-                        fontSize: 13, color: AppTheme.textPrimary),
-                    columnSpacing: 24,
-                    horizontalMargin: 16,
-                    dataRowMinHeight: 40,
-                    dataRowMaxHeight: 56,
-                    dividerThickness: 0.5,
-                    columns: columns,
-                    rows: rows,
+                    children: [
+                      _buildHeaderRow(),
+                      for (int i = 0; i < widget.rows.length; i++)
+                        _buildDataRow(i, widget.rows[i]),
+                    ],
                   ),
                 ),
               ),
@@ -70,7 +73,7 @@ class DataTableCard extends StatelessWidget {
           ),
         ),
         // Pagination
-        if (totalCount != null)
+        if (widget.totalCount != null)
           Container(
             height: 48,
             color: AppTheme.surface,
@@ -78,16 +81,16 @@ class DataTableCard extends StatelessWidget {
             child: Row(
               children: [
                 Text(
-                  '共 $totalCount 条记录',
+                  '共 ${widget.totalCount} 条记录',
                   style: const TextStyle(
                       fontSize: 13, color: AppTheme.textSecondary),
                 ),
                 const Spacer(),
                 _PaginationBar(
-                  page: page,
-                  total: totalCount!,
-                  pageSize: pageSize,
-                  onPageChanged: onPageChanged,
+                  page: widget.page,
+                  total: widget.totalCount!,
+                  pageSize: widget.pageSize,
+                  onPageChanged: widget.onPageChanged,
                 ),
               ],
             ),
@@ -95,6 +98,58 @@ class DataTableCard extends StatelessWidget {
       ],
     );
   }
+
+  TableRow _buildHeaderRow() {
+    return TableRow(
+      decoration: const BoxDecoration(color: Color(0xFFF0F4FF)),
+      children: widget.columns.map((col) {
+        return Padding(
+          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+          child: DefaultTextStyle(
+            style: const TextStyle(
+              fontSize: 13,
+              fontWeight: FontWeight.w600,
+              color: AppTheme.primaryDark,
+            ),
+            child: col.numeric
+                ? Align(alignment: Alignment.centerRight, child: col.label)
+                : col.label,
+          ),
+        );
+      }).toList(),
+    );
+  }
+
+  TableRow _buildDataRow(int rowIndex, DataRow row) {
+    return TableRow(
+      children: List.generate(row.cells.length, (colIndex) {
+        final cell = row.cells[colIndex];
+        final col = widget.columns[colIndex];
+        return MouseRegion(
+          onEnter: (_) => _hoveredRow.value = rowIndex,
+          onExit: (_) {
+            if (_hoveredRow.value == rowIndex) _hoveredRow.value = -1;
+          },
+          child: ValueListenableBuilder<int>(
+            valueListenable: _hoveredRow,
+            builder: (context, hovered, _) => Container(
+              constraints: const BoxConstraints(minHeight: 48),
+              alignment:
+                  col.numeric ? Alignment.centerRight : Alignment.centerLeft,
+              color: hovered == rowIndex ? const Color(0xFFF5F7FF) : null,
+              padding:
+                  const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
+              child: DefaultTextStyle(
+                style: const TextStyle(
+                    fontSize: 13, color: AppTheme.textPrimary),
+                child: cell.child,
+              ),
+            ),
+          ),
+        );
+      }),
+    );
+  }
 }
 
 class _PaginationBar extends StatelessWidget {