feat(runtime): add isolated same-origin canary gateway

apps/api/src/canary-cli.ts

@@ -0,0 +1,40 @@
+import { resolve } from 'node:path';
+
+import {
+  CANARY_DEFAULT_PORT,
+  CANARY_DEFAULT_UPSTREAM_PORT,
+  createCanaryGateway,
+} from './canary-gateway.ts';
+
+function environmentPort(name: string, fallback: number): number {
+  const value = process.env[name];
+  if (value === undefined || value === '') return fallback;
+  const port = Number(value);
+  if (!Number.isInteger(port)) throw new Error(`${name} must be an integer port`);
+  return port;
+}
+
+const gateway = createCanaryGateway({
+  distDir: resolve(process.env.CANARY_DIST_DIR ?? 'apps/web/dist'),
+  port: environmentPort('CANARY_PORT', CANARY_DEFAULT_PORT),
+  upstreamPort: environmentPort('CANARY_UPSTREAM_PORT', CANARY_DEFAULT_UPSTREAM_PORT),
+});
+
+let stopping = false;
+async function stop(signal: string): Promise<void> {
+  if (stopping) return;
+  stopping = true;
+  process.stdout.write(`Stopping canary gateway (${signal})\n`);
+  await gateway.stop();
+}
+
+process.once('SIGINT', () => void stop('SIGINT'));
+process.once('SIGTERM', () => void stop('SIGTERM'));
+
+try {
+  await gateway.start();
+  process.stdout.write(`Canary gateway listening at ${gateway.origin}\n`);
+} catch (error) {
+  process.stderr.write(`${error instanceof Error ? error.message : String(error)}\n`);
+  process.exitCode = 1;
+}