fix(dcrouter): persist proxy certificate validity dates and improve certificate status initialization

ts/opsserver/handlers/certificate.handler.ts

@@ -167,8 +167,16 @@ export class CertificateHandler {
             issuedAt = new Date(certData.created).toISOString();
           }
           issuer = 'smartacme-dns-01';
+        } else if (certData?.publicKey) {
+          // certStore has the cert — parse PEM for expiry
+          try {
+            const x509 = new plugins.crypto.X509Certificate(certData.publicKey);
+            expiryDate = new Date(x509.validTo).toISOString();
+            issuedAt = new Date(x509.validFrom).toISOString();
+          } catch { /* PEM parsing failed */ }
+          status = 'valid';
+          issuer = 'cert-store';
         } else if (certData) {
-          // certStore has the cert (no expiry metadata) — it's loaded and serving
           status = 'valid';
           issuer = 'cert-store';
         }