fix(domains): improve shared Nginx reconciliation logic in domain routes

next.config.ts

@@ -41,6 +41,13 @@ const securityHeaders = [
 const nextConfig: NextConfig = {
   allowedDevOrigins: ["localhost", "127.0.0.1", "192.168.12.11"],
   devIndicators: false,
+  experimental: {
+    // Domain provisioning can include SSH, Nginx validation/reload, and
+    // Certbot work. Keep the same-origin rewrite alive long enough for the
+    // backend to return its structured result instead of a proxy-generated
+    // non-JSON 500 response.
+    proxyTimeout: 5 * 60 * 1000,
+  },
   async rewrites() {
     const backendUrl =
       process.env.INTERNAL_API_URL ||

src/server/routes/domains.ts

@@ -1837,8 +1837,13 @@ export async function domainRoutes(app: FastifyInstance) {
     const willBeSharedNginx = isSharedNginxConfig(nextInput);
     const previousRootDomain = getDomainConfigAnchor([existing.name]);
     const nextRootDomain = getDomainConfigAnchor([nextInput.name]);
-    const previousSharedGroupNames =
+    const shouldReconcilePreviousShared =
       wasSharedNginx &&
+      (!willBeSharedNginx ||
+        existing.serverId !== (nextInput.serverId ?? null) ||
+        previousRootDomain !== nextRootDomain);
+    const previousSharedGroupNames =
+      shouldReconcilePreviousShared &&
       existing.serverId &&
       existing.targetContainerId &&
       existing.targetPort
@@ -1938,7 +1943,7 @@ export async function domainRoutes(app: FastifyInstance) {
     });
 
     if (
-      wasSharedNginx &&
+      shouldReconcilePreviousShared &&
       existing.serverId &&
       existing.targetContainerId &&
       existing.targetPort