Add runtime version reporting and display

test/server/version.test.js

@@ -0,0 +1,33 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import { buildVersionInfo } from '../../src/server/version.js';
+import { HARBOR_VERSIONS, versionCompatibility } from '../../src/shared/versions.js';
+
+test('component versions enforce one Harbor major and one Gateway major.minor', () => {
+  assert.deepEqual(versionCompatibility(HARBOR_VERSIONS), {
+    compatible: true,
+    major: true,
+    gateway: true,
+  });
+  assert.equal(versionCompatibility({
+    macClient: '1.9.4',
+    gatewayClient: '1.3.1',
+    gatewayBackend: '1.3.8',
+  }).compatible, true);
+  assert.equal(versionCompatibility({
+    macClient: '1.0.0',
+    gatewayClient: '1.3.0',
+    gatewayBackend: '1.4.0',
+  }).compatible, false);
+});
+
+test('runtime version info reports the installed sing-box binary', () => {
+  const run = () => ({ stdout: 'sing-box version 1.12.13\n', stderr: '' });
+  assert.deepEqual(buildVersionInfo('gateway', run), {
+    apiVersion: 1,
+    location: 'gateway',
+    components: { gatewayBackend: HARBOR_VERSIONS.gatewayBackend },
+    runtime: { singBox: '1.12.13' },
+  });
+});