fix: add HealthCheckListResponse type to match API response structure

- Added HealthCheckListResponse type { checks: [...], total: number }
- Updated healthChecksApi.list() return type to HealthCheckListResponse
- Fixed HostDetailPage to use res.data?.checks instead of Array.isArray
- Added Target column to health checks table
- Added git pre-commit/pre-push hooks to prevent format CI failures
- Updated lessons.md

frontend/src/api/client.ts

@@ -11,6 +11,7 @@ import type {
   HealthCheckWithResult,
   CreateHealthCheckRequest,
   UpdateHealthCheckRequest,
+  HealthCheckListResponse,
 } from '../types'
 
 const BASE_URL = '/api/v1'
@@ -273,7 +274,7 @@ export const settingsApi = {
 
 export const healthChecksApi = {
   list: (hostId: string) =>
-    apiClient.get<HealthCheckWithResult[]>(`/hosts/${hostId}/health-checks`),
+    apiClient.get<HealthCheckListResponse>(`/hosts/${hostId}/health-checks`),
 
   get: (hostId: string, checkId: string) =>
     apiClient.get<HealthCheckWithResult>(`/hosts/${hostId}/health-checks/${checkId}`),

frontend/src/types/index.ts

@@ -299,6 +299,11 @@ export interface HealthCheckWithResult extends HealthCheck {
   last_result?: HealthCheckResult
 }
 
+export interface HealthCheckListResponse {
+  checks: HealthCheckWithResult[]
+  total: number
+}
+
 export interface CreateHealthCheckRequest {
   name: string
   check_type: HealthCheckType