feat(monitor): 博主组头补上指标合计与本轮增量

折叠之后组头只有「N 篇」，等于把信息藏了起来 —— 折叠本来就该是收起来但仍可读

webui/src/components/monitor/NotesTable.tsx

@@ -39,6 +39,41 @@ const METRIC_COLUMNS: Array<{ key: keyof NoteMetrics; label: string }> = [
   { key: 'share_count', label: '分享' },
 ]
 
+/**
+ * 一个博主名下所有作品的指标合计。
+ *
+ * **全为 null 时结果是 null 而不是 0** —— 与项目一贯的口径一致：「0」是真实值，
+ * 「null」是不知道。合计成 0 会让"还没采到"看起来像"互动为零"。
+ */
+function sumMetrics(notes: MonitorNote[]) {
+  const values: Record<string, number | null> = {}
+  const deltas: Record<string, number | null> = {}
+
+  for (const column of METRIC_COLUMNS) {
+    let sum = 0
+    let sawValue = false
+    let deltaSum = 0
+    let sawDelta = false
+
+    for (const note of notes) {
+      const value = note.metrics[column.key]
+      if (value !== null && value !== undefined) {
+        sum += value
+        sawValue = true
+      }
+      const delta = note.deltas[column.key]
+      if (delta !== null && delta !== undefined) {
+        deltaSum += delta
+        sawDelta = true
+      }
+    }
+
+    values[column.key] = sawValue ? sum : null
+    deltas[column.key] = sawDelta ? deltaSum : null
+  }
+  return { values, deltas }
+}
+
 // 多出来的那个空列给展开箭头；分组表头会跨掉整行。
 const COLUMN_COUNT = METRIC_COLUMNS.length + 4
 
@@ -112,8 +147,11 @@ export function NotesTable({ taskId, onlyNew }: NotesTableProps) {
         <tbody>
           {groups.map((group) => {
             const isCollapsed = collapsed.has(group.key)
+            const totals = sumMetrics(group.notes)
             return (
               <Fragment key={group.key}>
+                {/* 组头与数据行**列对齐**：每个指标列给出该博主的合计，下面再带本轮增量。
+                    折叠之后如果什么都看不到，那折叠就只是把信息藏起来了。 */}
                 <tr
                   onClick={() => toggleCreator(group.key)}
                   className="border-t border-cyber-border-subtle bg-cyber-bg-tertiary/50 cursor-pointer hover:bg-cyber-bg-elevated/50"
@@ -125,18 +163,25 @@ export function NotesTable({ taskId, onlyNew }: NotesTableProps) {
                       <ChevronDown className="w-3 h-3" />
                     )}
                   </td>
-                  <td colSpan={COLUMN_COUNT - 1} className="py-1.5 px-2">
+                  <td className="py-1.5 px-2">
                     <span className="flex items-center gap-1.5">
                       <Users className="w-3 h-3 text-cyber-neon-cyan" />
                       <span className="text-cyber-text-primary">
                         {group.name || '未知博主'}
                       </span>
                       <span className="text-cyber-text-muted">{group.notes.length} 篇</span>
-                      {isCollapsed && (
-                        <span className="text-cyber-text-muted">（已折叠）</span>
-                      )}
                     </span>
                   </td>
+                  {METRIC_COLUMNS.map((column) => (
+                    <td key={column.key} className="py-1.5 px-2">
+                      <MetricCell
+                        value={totals.values[column.key]}
+                        delta={totals.deltas[column.key]}
+                      />
+                    </td>
+                  ))}
+                  <td />
+                  <td />
                 </tr>
 
                 {!isCollapsed &&