feat: 新增 Skills Usage 监控统计与图表 (#668)

* feat: add skills usage monitoring

* fix: localize Skills Usage page copy

* fix: keep Skills Usage labels compact

packages/server/src/routes/hermes/skills.ts

@@ -4,6 +4,7 @@ import * as ctrl from '../../controllers/hermes/skills'
 export const skillRoutes = new Router()
 
 skillRoutes.get('/api/hermes/skills', ctrl.list)
+skillRoutes.get('/api/hermes/skills/usage/stats', ctrl.usageStats)
 skillRoutes.put('/api/hermes/skills/toggle', ctrl.toggle)
 skillRoutes.put('/api/hermes/skills/pin', ctrl.pin_)
 skillRoutes.get('/api/hermes/skills/:category/:skill/files', ctrl.listFiles)