결재 템플릿 단계 적용 구현

- ApprovalTemplate 엔티티·DTO·원격 리포지토리 추가
- ApprovalController에 템플릿 로딩/적용 상태와 assignSteps 호출 연동
- ApprovalPage 단계 탭에 템플릿 선택 UI 및 적용 확인 다이얼로그 구현
- 템플릿 적용 단위 테스트와 IMPLEMENTATION_TASKS 현황 갱신

lib/widgets/components/superport_table.dart

@@ -0,0 +1,58 @@
+import 'package:flutter/material.dart';
+import 'package:shadcn_ui/shadcn_ui.dart';
+
+/// ShadTable.list를 감싼 공통 테이블 래퍼.
+class SuperportTable extends StatelessWidget {
+  const SuperportTable({
+    super.key,
+    required this.columns,
+    required this.rows,
+    this.columnSpanExtent,
+    this.rowHeight = 56,
+    this.onRowTap,
+    this.emptyLabel = '데이터가 없습니다.',
+  });
+
+  final List<Widget> columns;
+  final List<List<Widget>> rows;
+  final TableSpanExtent? Function(int index)? columnSpanExtent;
+  final double rowHeight;
+  final void Function(int index)? onRowTap;
+  final String emptyLabel;
+
+  @override
+  Widget build(BuildContext context) {
+    if (rows.isEmpty) {
+      final theme = ShadTheme.of(context);
+      return Padding(
+        padding: const EdgeInsets.all(32),
+        child: Center(
+          child: Text(emptyLabel, style: theme.textTheme.muted),
+        ),
+      );
+    }
+
+    final tableRows = [
+      for (final row in rows)
+        row
+            .map(
+              (cell) => cell is ShadTableCell ? cell : ShadTableCell(child: cell),
+            )
+            .toList(),
+    ];
+
+    return ShadTable.list(
+      header: columns
+          .map(
+            (cell) => cell is ShadTableCell
+                ? cell
+                : ShadTableCell.header(child: cell),
+          )
+          .toList(),
+      columnSpanExtent: columnSpanExtent,
+      rowSpanExtent: (_) => FixedTableSpanExtent(rowHeight),
+      onRowTap: onRowTap,
+      children: tableRows,
+    );
+  }
+}