feat: [approvals] 결재선 에디터 2패널 UI/UX 개선

- 좌측 패널: 부서별 인원 목록 (접이식 그룹핑, 검색 필터)
- 우측 패널: 결재선 (SortableJS 드래그앤드롭 순서 변경)
- 부서별 전체 인원 API 추가 (GET /api/admin/tenant-users/list)
- 결재/합의/참조 유형별 요약 바 추가
- position_key → positions 테이블 조인으로 직위 라벨 표시

app/Http/Controllers/Api/Admin/TenantUserApiController.php

@@ -50,4 +50,80 @@ public function search(Request $request): JsonResponse
             'data' => $users,
         ]);
     }
+
+    /**
+     * 테넌트 전체 인원 목록 (부서별 그룹핑, 결재선 에디터용)
+     */
+    public function list(): JsonResponse
+    {
+        $tenantId = session('selected_tenant_id');
+
+        $users = DB::table('users')
+            ->join('user_tenants', function ($join) use ($tenantId) {
+                $join->on('users.id', '=', 'user_tenants.user_id')
+                    ->where('user_tenants.tenant_id', $tenantId)
+                    ->where('user_tenants.is_active', true);
+            })
+            ->leftJoin('tenant_user_profiles as tp', function ($join) use ($tenantId) {
+                $join->on('tp.user_id', '=', 'users.id')
+                    ->where('tp.tenant_id', $tenantId);
+            })
+            ->leftJoin('departments', 'departments.id', '=', 'tp.department_id')
+            ->leftJoin('positions as pos_rank', function ($join) use ($tenantId) {
+                $join->on('pos_rank.tenant_id', '=', DB::raw($tenantId))
+                    ->where('pos_rank.type', 'rank')
+                    ->whereRaw('pos_rank.`key` COLLATE utf8mb4_unicode_ci = tp.position_key COLLATE utf8mb4_unicode_ci');
+            })
+            ->leftJoin('positions as pos_title', function ($join) use ($tenantId) {
+                $join->on('pos_title.tenant_id', '=', DB::raw($tenantId))
+                    ->where('pos_title.type', 'title')
+                    ->whereRaw('pos_title.`key` COLLATE utf8mb4_unicode_ci = tp.job_title_key COLLATE utf8mb4_unicode_ci');
+            })
+            ->whereNull('users.deleted_at')
+            ->orderBy('departments.name')
+            ->orderBy('users.name')
+            ->select([
+                'users.id',
+                'users.name',
+                'tp.department_id',
+                'departments.name as department_name',
+                DB::raw('COALESCE(pos_rank.name, tp.position_key, \'\') as position'),
+                DB::raw('COALESCE(pos_title.name, tp.job_title_key, \'\') as job_title'),
+            ])
+            ->get();
+
+        $grouped = $users->groupBy(fn ($u) => $u->department_id ?? 'none');
+
+        $data = [];
+        foreach ($grouped as $deptId => $deptUsers) {
+            $first = $deptUsers->first();
+            $data[] = [
+                'department_id' => $deptId === 'none' ? null : (int) $deptId,
+                'department_name' => $deptId === 'none' ? '미배정' : $first->department_name,
+                'users' => $deptUsers->map(fn ($u) => [
+                    'id' => $u->id,
+                    'name' => $u->name,
+                    'position' => $u->position,
+                    'job_title' => $u->job_title,
+                ])->values()->toArray(),
+            ];
+        }
+
+        // 미배정 그룹을 마지막으로
+        usort($data, function ($a, $b) {
+            if ($a['department_id'] === null) {
+                return 1;
+            }
+            if ($b['department_id'] === null) {
+                return -1;
+            }
+
+            return strcmp($a['department_name'], $b['department_name']);
+        });
+
+        return response()->json([
+            'success' => true,
+            'data' => $data,
+        ]);
+    }
 }