feat(access-logs): 日志明细支持按状态码筛选并折叠次要搜索项，修复首页来源分布无数据

- 修复 PostgreSQL/SQLite 日志库下首页「来源分布」卡片无数据：RegionCounts 对空
  节点 ID 误拼 node_id = '' 恒空条件，改为空节点 ID 表示全节点聚合（对齐 CH 语义），
  并过滤空白归属地
- /access-logs?tab=list 新增状态码筛选：状态码下拉含常用 2xx/3xx/4xx/5xx 选项，
  校验 100-599，非法值返回 400；ClickHouse 与 PostgreSQL/SQLite 日志库均支持
- 搜索框折叠：默认仅显示来源 IP 与状态码，节点 ID/访问域名/请求路径折叠进
  「更多筛选」

internal/repository/analytics/access_log_test.go

@@ -45,6 +45,16 @@ func TestBuildUserAccessLogFilterClause_EmptyUserIDs(t *testing.T) {
 	assert.False(t, ok)
 }
 
+func TestBuildNodeAccessLogFilterClause_StatusCode(t *testing.T) {
+	clause, args := buildNodeAccessLogFilterClause(NodeAccessLogFilter{StatusCode: 404})
+	assert.Equal(t, "status_code = ?", clause)
+	assert.Equal(t, []any{404}, args)
+
+	clause, args = buildNodeAccessLogFilterClause(NodeAccessLogFilter{})
+	assert.Equal(t, "1", clause)
+	assert.Nil(t, args)
+}
+
 func TestCountAccessLogs_EmptyUserIDs(t *testing.T) {
 	count, err := CountAccessLogs(context.Background(), AccessLogFilter{UserIDs: []uint64{}})
 	require.NoError(t, err)

internal/repository/analytics/node_access_log_filter.go

@@ -11,7 +11,7 @@ import (
 )
 
 const (
-	nodeAccessLogFilterClauseCapacity = 6
+	nodeAccessLogFilterClauseCapacity = 7
 
 	nodeAccessLogSortDesc     = "DESC"
 	nodeAccessLogSortAsc      = "ASC"
@@ -55,6 +55,10 @@ func buildNodeAccessLogFilterClause(filter NodeAccessLogFilter) (string, []any)
 		parts = append(parts, "path LIKE ?")
 		args = append(args, trimmed+"%")
 	}
+	if filter.StatusCode > 0 {
+		parts = append(parts, "status_code = ?")
+		args = append(args, filter.StatusCode)
+	}
 	if !filter.Since.IsZero() {
 		parts = append(parts, "logged_at >= ?")
 		args = append(args, filter.Since.UTC())