feat(server): 健康检查增强 — 新增 /health/ready 就绪检查

- 保留 /health 轻量存活检查
- 新增 /health/ready 含 DB ping + Redis ping 并行检测
- 返回 status(ok/degraded/unavailable) + 各组件延迟和错误信息

crates/erp-server/src/handlers/health.rs

@@ -13,9 +13,7 @@ pub struct HealthResponse {
     pub modules: Vec<String>,
 }
 
-/// GET /health
-///
-/// 服务健康检查，返回运行状态和已注册模块列表
+/// GET /health — 轻量存活检查
 pub async fn health_check(State(state): State<AppState>) -> Json<HealthResponse> {
     let modules = state
         .module_registry
@@ -31,6 +29,106 @@ pub async fn health_check(State(state): State<AppState>) -> Json<HealthResponse>
     })
 }
 
-pub fn health_check_router() -> Router<AppState> {
-    Router::new().route("/health", get(health_check))
+#[derive(Debug, Serialize)]
+pub struct ReadyResponse {
+    pub status: String,
+    pub version: String,
+    pub database: ComponentStatus,
+    pub redis: ComponentStatus,
+    pub modules: Vec<String>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct ComponentStatus {
+    pub status: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub latency_ms: Option<u64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+}
+
+/// GET /health/ready — 就绪检查（含 DB + Redis 连通性）
+pub async fn readiness_check(State(state): State<AppState>) -> Json<ReadyResponse> {
+    let modules = state
+        .module_registry
+        .modules()
+        .iter()
+        .map(|m| m.name().to_string())
+        .collect();
+
+    let (db_status, redis_status) = tokio::join!(
+        check_database(&state.db),
+        check_redis(&state.redis),
+    );
+
+    let overall = if db_status.status == "ok" && redis_status.status == "ok" {
+        "ok"
+    } else if db_status.status == "ok" {
+        "degraded"
+    } else {
+        "unavailable"
+    };
+
+    Json(ReadyResponse {
+        status: overall.to_string(),
+        version: env!("CARGO_PKG_VERSION").to_string(),
+        database: db_status,
+        redis: redis_status,
+        modules,
+    })
+}
+
+async fn check_database(db: &sea_orm::DatabaseConnection) -> ComponentStatus {
+    use sea_orm::ConnectionTrait;
+    let start = std::time::Instant::now();
+    let stmt = sea_orm::Statement::from_string(
+        sea_orm::DatabaseBackend::Postgres,
+        "SELECT 1".to_string(),
+    );
+    match db.query_one(stmt).await {
+        Ok(_) => ComponentStatus {
+            status: "ok".to_string(),
+            latency_ms: Some(start.elapsed().as_millis() as u64),
+            error: None,
+        },
+        Err(e) => ComponentStatus {
+            status: "error".to_string(),
+            latency_ms: Some(start.elapsed().as_millis() as u64),
+            error: Some(e.to_string()),
+        },
+    }
+}
+
+async fn check_redis(client: &redis::Client) -> ComponentStatus {
+    let start = std::time::Instant::now();
+    match client.get_multiplexed_async_connection().await {
+        Ok(mut conn) => {
+            match redis::cmd("PING")
+                .query_async::<String>(&mut conn)
+                .await
+            {
+                Ok(_) => ComponentStatus {
+                    status: "ok".to_string(),
+                    latency_ms: Some(start.elapsed().as_millis() as u64),
+                    error: None,
+                },
+                Err(e) => ComponentStatus {
+                    status: "error".to_string(),
+                    latency_ms: Some(start.elapsed().as_millis() as u64),
+                    error: Some(e.to_string()),
+                },
+            }
+        }
+        Err(e) => ComponentStatus {
+            status: "error".to_string(),
+            latency_ms: Some(start.elapsed().as_millis() as u64),
+            error: Some(e.to_string()),
+        },
+    }
+}
+
+pub fn health_check_router() -> Router<AppState> {
+    Router::new()
+        .route("/health", get(health_check))
+        .route("/health/ready", get(readiness_check))
 }