新增数据重置功能：管理员可一键清空所有行情数据，需输入确认文字防误操作

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

web/backend/internal/router/router.go

@@ -38,6 +38,7 @@ func New(d *handlers.Deps, dist fs.FS) http.Handler {
 				r.Post("/admin/users", d.AdminCreateUser)
 				r.Patch("/admin/users/{id}", d.AdminPatchUser)
 				r.Delete("/admin/users/{id}", d.AdminDeleteUser)
+				r.Post("/admin/reset-data", d.AdminResetData)
 			})
 		})
 	})