feat: add e2e integration tests and canonical versioning

tests/integration/api-keys.test.ts

@@ -0,0 +1,11 @@
+import { describe, expect, test } from 'vitest';
+import { getRuntimeClient, HS_VERSIONS } from './setup/env';
+
+describe.for(HS_VERSIONS)('Headscale %s: API Keys', (version) => {
+	test('api keys can be fetched', async () => {
+		const client = await getRuntimeClient(version);
+		const apiKeys = await client.getApiKeys();
+		expect(Array.isArray(apiKeys)).toBe(true);
+		expect(apiKeys.length).toBe(1);
+	});
+});