fix(FR-1412): optimize agent filtering and fix pagination count (#4192)

resolves #4191 ([FR-1412](https://lablup.atlassian.net/browse/FR-1412))

## Summary

Fixes pagination issue in the Resource Summary tab (AgentSummaryList component) where pagination would be stuck at 1 when selecting small page sizes like 10 or 20. This was caused by incorrect client-side filtering that affected the pagination total count.

## Changes Made

1. **Moved sFTP resource group filtering from client-side to server-side**:
   - Added `mergeFilterValues` import from `backend.ai-ui`
   - Created `sftpExclusionFilter` using `!(scaling_group in ["group1", "group2"])` syntax
   - Updated GraphQL query to merge user filter with sFTP exclusion filter

2. **Removed inefficient client-side filtering logic**:
   - Removed `filteredAgentSummaryList` that was filtering after data fetch
   - Updated table `dataSource` to use `agent_summary_list?.items` directly

3. **Fixed pagination total count**:
   - Changed pagination total from `filteredAgentSummaryList?.length` to `agent_summary_list?.total_count`
   - This ensures pagination uses the correct server-side filtered count

## Impact

- ✅ Fixes pagination issue where list wouldn't appear with small page sizes
- ✅ Improves performance by filtering on server-side instead of client-side
- ✅ Reduces data transfer by excluding sFTP agents at query level
- ✅ Maintains existing filtering functionality

## Testing

- Verify pagination works correctly with different page sizes (10, 20, 50, etc.)
- Confirm sFTP resource groups are still properly excluded from the list
- Check that user filters (ID, schedulable status) still work as expected

**Checklist:**

- [x] Fix addresses the root cause of pagination issue
- [x] Server-side filtering implementation follows existing patterns
- [x] No breaking changes to existing functionality
- [x] Performance improvement through reduced client-side processing

[FR-1412]: https://lablup.atlassian.net/browse/FR-1412?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: ironAiken2

react/src/components/AgentSummaryList.tsx

@@ -30,6 +30,7 @@ import {
   BAITable,
   BAIFlex,
   BAIPropertyFilter,
+  mergeFilterValues,
 } from 'backend.ai-ui';
 import _ from 'lodash';
 import React, { useState, useTransition } from 'react';
@@ -82,6 +83,11 @@ const AgentSummaryList: React.FC<AgentSummaryListProps> = ({
     });
   const { sftpResourceGroups } = useResourceGroupsForCurrentProject();
 
+  const sftpExclusionFilter =
+    sftpResourceGroups && sftpResourceGroups.length > 0
+      ? `!(scaling_group in [${sftpResourceGroups.map((group) => `"${group}"`).join(', ')}])`
+      : undefined;
+
   const { agent_summary_list } = useLazyLoadQuery<AgentSummaryListQuery>(
     graphql`
       query AgentSummaryListQuery(
@@ -114,7 +120,7 @@ const AgentSummaryList: React.FC<AgentSummaryListProps> = ({
     {
       limit: baiPaginationOption.limit,
       offset: baiPaginationOption.offset,
-      filter: filterString,
+      filter: mergeFilterValues([filterString, sftpExclusionFilter]),
       order,
       status: selectedStatus,
     },
@@ -124,12 +130,6 @@ const AgentSummaryList: React.FC<AgentSummaryListProps> = ({
     },
   );
 
-  // Hide sFTP upload agents
-  const filteredAgentSummaryList = _.filter(
-    agent_summary_list?.items,
-    (item) => !_.includes(sftpResourceGroups, item?.scaling_group),
-  );
-
   const columns: ColumnsType<AgentSummary> = [
     {
       title: <>ID</>,
@@ -421,7 +421,7 @@ const AgentSummaryList: React.FC<AgentSummaryListProps> = ({
         bordered
         scroll={{ x: 'max-content' }}
         rowKey={'id'}
-        dataSource={filterOutNullAndUndefined(filteredAgentSummaryList)}
+        dataSource={filterOutNullAndUndefined(agent_summary_list?.items)}
         showSorterTooltip={false}
         columns={
           _.filter(
@@ -431,7 +431,7 @@ const AgentSummaryList: React.FC<AgentSummaryListProps> = ({
         }
         pagination={{
           pageSize: tablePaginationOption.pageSize,
-          total: filteredAgentSummaryList?.length || 0,
+          total: agent_summary_list?.total_count || 0,
           current: tablePaginationOption.current,
           onChange(page, pageSize) {
             startPageChangeTransition(() => {