fix(build): enforce stricter TypeScript checks and update build dependencies

test/test.features.ts

@@ -153,6 +153,9 @@ tap.test('isLocalPortUnused should detect used local port', async () => {
 // findFreePort tests
 tap.test('findFreePort should find an available port in range', async () => {
   const freePort = await sharedSn.findFreePort(49152, 49200);
+  if (freePort === null) {
+    throw new Error('Expected to find a free port in test range');
+  }
   expect(freePort).toBeGreaterThanOrEqual(49152);
   expect(freePort).toBeLessThanOrEqual(49200);
 

test/test.ts

@@ -47,6 +47,9 @@ tap.test('should get the default gateway', async () => {
   console.log(defaultGw);
   // verify default gateway contains ipv4 and ipv6 info
   expect(defaultGw).toBeDefined();
+  if (!defaultGw) {
+    throw new Error('Expected a default gateway');
+  }
   expect(defaultGw.ipv4).toBeDefined();
   expect(defaultGw.ipv6).toBeDefined();
 });