fix: SkillsUsage 页面样式修复与 API server skill usage 统计 (#698)

* Reapply "feat: 新增 Skills Usage 监控统计与图表 (#668)" (#670)

This reverts commit 91de3b12a1.

* fix: count API-server skill usage

* fix: align SkillsUsageView header with other pages and update sidebar icon

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Zhicheng Han <zhicheng.han@mathematik.uni-goettingen.de>
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

packages/client/src/api/hermes/skills.ts

@@ -45,11 +45,52 @@ export interface SkillsData {
   archived: SkillInfo[]
 }
 
+export interface SkillUsageRow {
+  skill: string
+  view_count: number
+  manage_count: number
+  total_count: number
+  percentage: number
+  last_used_at: number | null
+}
+
+export interface SkillUsageDailySkillRow {
+  skill: string
+  view_count: number
+  manage_count: number
+  total_count: number
+}
+
+export interface SkillUsageDailyRow {
+  date: string
+  view_count: number
+  manage_count: number
+  total_count: number
+  skills: SkillUsageDailySkillRow[]
+}
+
+export interface SkillUsageStats {
+  period_days: number
+  summary: {
+    total_skill_loads: number
+    total_skill_edits: number
+    total_skill_actions: number
+    distinct_skills_used: number
+  }
+  by_day: SkillUsageDailyRow[]
+  top_skills: SkillUsageRow[]
+}
+
 export async function fetchSkills(): Promise<SkillsData> {
   const res = await request<SkillListResponse>('/api/hermes/skills')
   return { categories: res.categories, archived: res.archived ?? [] }
 }
 
+export async function fetchSkillUsageStats(days = 7): Promise<SkillUsageStats> {
+  const params = new URLSearchParams({ days: String(days) })
+  return request<SkillUsageStats>(`/api/hermes/skills/usage/stats?${params}`)
+}
+
 export async function fetchSkillContent(skillPath: string): Promise<string> {
   const res = await request<{ content: string }>(`/api/hermes/skills/${skillPath}`)
   return res.content