feat(health)!: promote to v1.0.0 — configurable check timeout via NewHandlerWithConfig

Add Config struct and NewHandlerWithConfig(logger, cfg, checks...) constructor.
Config.CheckTimeout sets the per-request deadline for all health checks; zero
value defaults to 5 seconds. NewHandler remains unchanged as a backward-compatible
wrapper. API committed as stable.

health.go

@@ -48,23 +48,44 @@ type Response struct {
 	Components map[string]ComponentStatus `json:"components"`
 }
 
-type handler struct {
-	logger Logger
-	checks []Checkable
+// Config configures a health handler.
+// The zero value is valid: 5-second check timeout.
+type Config struct {
+	// CheckTimeout is the per-request deadline for all health checks.
+	// Defaults to 5 seconds when zero.
+	CheckTimeout time.Duration
 }
 
-// NewHandler returns an http.Handler for the health endpoint.
+const defaultCheckTimeout = 5 * time.Second
+
+type handler struct {
+	logger  Logger
+	checks  []Checkable
+	timeout time.Duration
+}
+
+// NewHandler returns an http.Handler for the health endpoint with default configuration.
 // Runs all checks concurrently with a 5-second timeout.
 // Returns 200 (UP/DEGRADED) or 503 (DOWN).
 func NewHandler(logger Logger, checks ...Checkable) http.Handler {
-	return &handler{logger: logger, checks: checks}
+	return NewHandlerWithConfig(logger, Config{}, checks...)
+}
+
+// NewHandlerWithConfig returns an http.Handler configured by cfg.
+// If cfg.CheckTimeout is zero, a 5-second default is used.
+func NewHandlerWithConfig(logger Logger, cfg Config, checks ...Checkable) http.Handler {
+	timeout := cfg.CheckTimeout
+	if timeout == 0 {
+		timeout = defaultCheckTimeout
+	}
+	return &handler{logger: logger, checks: checks, timeout: timeout}
 }
 
 func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	logger := h.logger.WithContext(r.Context())
 	logger.Debug("health: running checks")
 
-	ctx, cancel := context.WithTimeout(r.Context(), 5*time.Second)
+	ctx, cancel := context.WithTimeout(r.Context(), h.timeout)
 	defer cancel()
 
 	type result struct {