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

This reverts commit ce08d2b05a.

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

@@ -6,7 +6,6 @@ import {
   safeReadFile, extractDescription, listFilesRecursive, getHermesDir,
 } from '../../services/config-helpers'
 import { pinSkill } from '../../services/hermes/hermes-cli'
-import { getSkillUsageStatsFromDb } from '../../db/hermes/sessions-db'
 
 /** Read bundled manifest as a name→hash map from ~/.hermes/skills/.bundled_manifest */
 function readBundledManifest(manifestContent: string | null): Map<string, string> {
@@ -240,18 +239,6 @@ export async function list(ctx: any) {
   }
 }
 
-export async function usageStats(ctx: any) {
-  const rawDays = parseInt(String(ctx.query?.days ?? '7'), 10)
-  const days = Number.isFinite(rawDays) && rawDays > 0 ? Math.min(rawDays, 365) : 7
-
-  try {
-    ctx.body = await getSkillUsageStatsFromDb(days)
-  } catch (err: any) {
-    ctx.status = 500
-    ctx.body = { error: `Failed to read skill usage stats: ${err.message}` }
-  }
-}
-
 export async function toggle(ctx: any) {
   const { name, enabled } = ctx.request.body as { name?: string; enabled?: boolean }
   if (!name || typeof enabled !== 'boolean') {