refactor(entrypoint): move route registry into entrypoint context

Replace global routes registry with entrypoint-scoped pools and
context lookups, and centralize API/metrics startup in config state.

internal/autocert/types/context.go

@@ -0,0 +1,16 @@
+package autocert
+
+import "context"
+
+type ContextKey struct{}
+
+func SetCtx(ctx interface{ SetValue(any, any) }, p Provider) {
+	ctx.SetValue(ContextKey{}, p)
+}
+
+func FromCtx(ctx context.Context) Provider {
+	if provider, ok := ctx.Value(ContextKey{}).(Provider); ok {
+		return provider
+	}
+	return nil
+}

internal/autocert/types/provider.go

@@ -7,7 +7,6 @@ import (
 )
 
 type Provider interface {
-	Setup() error
 	GetCert(*tls.ClientHelloInfo) (*tls.Certificate, error)
 	ScheduleRenewalAll(task.Parent)
 	ObtainCertAll() error