Migrate CLI E2E tests to Node.js 26

Run the CLI subprocess suites and benchmark tools as native TypeScript with
node:test, and move them under test/e2e-cli.

Update CI and Compose runners, run local smoke tests on Linux, macOS, and
Windows, and collect source-mapped CLI coverage with c8.

test/e2e-cli/helpers/net.ts

@@ -0,0 +1,59 @@
+import { createConnection, createServer } from "node:net";
+
+type WaitForPortOptions = { timeoutMs?: number; intervalMs?: number; connectTimeoutMs?: number };
+
+async function connectWithTimeout(hostname: string, port: number, timeoutMs: number): Promise<void> {
+    await new Promise<void>((resolve, reject) => {
+        const socket = createConnection({ host: hostname, port });
+        socket.setTimeout(timeoutMs, () => socket.destroy(new Error(`connect timeout after ${timeoutMs}ms`)));
+        socket.once("error", reject);
+        socket.once("connect", () => {
+            socket.destroy();
+            resolve();
+        });
+    });
+}
+
+export async function waitForPort(hostname: string, port: number, options: WaitForPortOptions = {}): Promise<void> {
+    const timeoutMs = options.timeoutMs ?? 15000;
+    const intervalMs = options.intervalMs ?? 250;
+    const started = Date.now();
+    let lastError: unknown;
+    while (Date.now() - started < timeoutMs) {
+        try {
+            await connectWithTimeout(hostname, port, options.connectTimeoutMs ?? 1000);
+            return;
+        } catch (error) {
+            lastError = error;
+            await new Promise((resolve) => setTimeout(resolve, intervalMs));
+        }
+    }
+    throw new Error(
+        `Port ${hostname}:${port} did not become ready within ${timeoutMs}ms` +
+            (lastError ? ` (last error: ${String(lastError)})` : "")
+    );
+}
+
+export async function getFreePort(hostname = "127.0.0.1"): Promise<number> {
+    const server = createServer();
+    await new Promise<void>((resolve, reject) => {
+        server.once("error", reject);
+        server.listen(0, hostname, resolve);
+    });
+    const address = server.address();
+    await new Promise<void>((resolve, reject) => server.close((error) => (error ? reject(error) : resolve())));
+    if (!address || typeof address === "string") throw new Error("The listener did not bind a TCP port");
+    return address.port;
+}
+
+export async function getOptimalLoopbackIp(): Promise<string> {
+    for (const hostname of ["127.0.0.1", "::1"]) {
+        try {
+            await getFreePort(hostname);
+            return hostname;
+        } catch {
+            /* Try the other loopback family. */
+        }
+    }
+    return "127.0.0.1";
+}