fix(login): http 2 memory leak's (#11830)

# Which Problems Are Solved
All http 2 based connect-es clients caused memory leaks in our testing
using the login v2 application as the host.

# How the Problems Are Solved
Switch to connect-rpc based http 1.1 transport for the login v2

# Additional Changes
Improved the otel interceptor implementation and tests.

# Additional Context
- connect-rpc is only enabled for v2 API's so we have to make sure to
not use any v1 apis in the login but this should be the case anyways.
- Discussion #10562

---------

Co-authored-by: Max Peintner <[email protected]>

apps/login/dockerized/otel/mock-zitadel-server.js

@@ -1,10 +1,7 @@
 /**
- * Mock Zitadel Connect/gRPC server for testing trace propagation.
+ * Mock Zitadel ConnectRPC server for testing trace propagation.
  * Captures incoming headers and writes them to a file for test assertions.
- *
- * Uses HTTP/2 with cleartext (h2c) to support gRPC protocol.
  */
-const http2 = require("http2");
 const http = require("http");
 const fs = require("fs");
 const path = require("path");
@@ -34,21 +31,18 @@ function safeJsonStringify(value) {
 // Store captured requests
 const capturedRequests = [];
 
-// Handle HTTP/2 request
-function handleRequest(stream, headers, isHttp2 = true) {
-  const method = isHttp2 ? headers[":method"] : headers.method;
-  const url = isHttp2 ? headers[":path"] : headers.url;
+const server = http.createServer((req, res) => {
+  const { method, url } = req;
 
   // Capture trace headers
   const traceHeaders = {
     timestamp: new Date().toISOString(),
-    method: method,
-    url: url,
-    traceparent: headers["traceparent"] || null,
-    tracestate: headers["tracestate"] || null,
-    baggage: headers["baggage"] || null,
-    grpcAcceptEncoding: headers["grpc-accept-encoding"] || null,
-    contentType: headers["content-type"] || null,
+    method,
+    url,
+    traceparent: req.headers["traceparent"] || null,
+    tracestate: req.headers["tracestate"] || null,
+    baggage: req.headers["baggage"] || null,
+    contentType: req.headers["content-type"] || null,
   };
 
   capturedRequests.push(traceHeaders);
@@ -60,24 +54,9 @@ function handleRequest(stream, headers, isHttp2 = true) {
   console.log(`[${traceHeaders.timestamp}] ${method} ${url}`);
   console.log(`  traceparent: ${traceHeaders.traceparent || "(none)"}`);
 
-  // Helper to send response
   const sendResponse = (statusCode, contentType, body) => {
-    if (isHttp2) {
-      stream.respond({
-        ":status": statusCode,
-        "content-type": contentType,
-        "grpc-status": "0",
-        "grpc-message": "OK",
-      });
-      stream.end(body);
-    } else {
-      stream.writeHead(statusCode, {
-        "Content-Type": contentType,
-        "grpc-status": "0",
-        "grpc-message": "OK",
-      });
-      stream.end(body);
-    }
+    res.writeHead(statusCode, { "Content-Type": contentType });
+    res.end(body);
   };
 
   // Health check
@@ -92,7 +71,7 @@ function handleRequest(stream, headers, isHttp2 = true) {
     return;
   }
 
-  // Mock Connect/gRPC responses
+  // Mock ConnectRPC responses
   // These are minimal responses to prevent the login app from crashing
   if (url.includes("GetLoginSettings") || url.includes("SettingsService")) {
     sendResponse(200, "application/json", safeJsonStringify({ settings: {} }));
@@ -109,47 +88,20 @@ function handleRequest(stream, headers, isHttp2 = true) {
   } else {
     sendResponse(200, "application/json", safeJsonStringify({}));
   }
-}
-
-// Create HTTP/2 server (cleartext for testing)
-const http2Server = http2.createServer();
-
-http2Server.on("stream", (stream, headers) => {
-  handleRequest(stream, headers, true);
 });
 
-http2Server.on("error", (err) => console.error("HTTP/2 error:", err));
+server.on("error", (err) => console.error("Server error:", err));
 
-// Also create HTTP/1.1 server for health checks from wget
-const httpServer = http.createServer((req, res) => {
-  // Create a headers object compatible with handleRequest
-  const headers = {
-    method: req.method,
-    url: req.url,
-    ...req.headers,
-  };
-  handleRequest(res, headers, false);
-});
-
-// Start HTTP/2 server on main port
-http2Server.listen(PORT, "0.0.0.0", () => {
-  console.log(`Mock Zitadel HTTP/2 server listening on port ${PORT}`);
+server.listen(PORT, "0.0.0.0", () => {
+  console.log(`Mock Zitadel server listening on port ${PORT}`);
   console.log(`Captured headers will be written to: ${HEADERS_FILE}`);
 });
 
-// Start HTTP/1.1 server on a different port for health checks
-const HEALTH_PORT = 7432;
-httpServer.listen(HEALTH_PORT, "0.0.0.0", () => {
-  console.log(`Mock Zitadel HTTP/1.1 health server listening on port ${HEALTH_PORT}`);
-});
-
 // Graceful shutdown
 process.on("SIGTERM", () => {
-  console.log("Shutting down mock servers...");
-  http2Server.close(() => {
-    httpServer.close(() => {
-      console.log("Mock servers stopped");
-      process.exit(0);
-    });
+  console.log("Shutting down mock server...");
+  server.close(() => {
+    console.log("Mock server stopped");
+    process.exit(0);
   });
 });