Update VPN proxy client behavior

test/web/client-controls.test.js

@@ -93,6 +93,74 @@ test('copy uses the synchronous native path available on gateway HTTP', async ()
   assert.equal(textarea.removed, true);
 });
 
+test('copy prefers the Clipboard API when it is available', async () => {
+  const writes = [];
+  let legacyCalls = 0;
+
+  await copyText('socks5://127.0.0.1:8082', {
+    clipboard: { writeText: async (text) => writes.push(text) },
+    documentRef: { execCommand: () => { legacyCalls += 1; } },
+  });
+
+  assert.deepEqual(writes, ['socks5://127.0.0.1:8082']);
+  assert.equal(legacyCalls, 0);
+});
+
+test('copy falls back after the Clipboard API rejects', async () => {
+  const textarea = {
+    style: {},
+    setAttribute() {},
+    select() {},
+    remove() { this.removed = true; },
+  };
+  const documentRef = {
+    body: { append() {} },
+    createElement: () => textarea,
+    execCommand: () => true,
+  };
+
+  await copyText('192.168.50.111', {
+    clipboard: { writeText: async () => { throw new Error('denied'); } },
+    documentRef,
+  });
+
+  assert.equal(textarea.removed, true);
+});
+
+test('copy rejects and removes the temporary textarea when the fallback fails', async () => {
+  const textarea = {
+    style: {},
+    setAttribute() {},
+    select() {},
+    remove() { this.removed = true; },
+  };
+  const documentRef = {
+    body: { append() {} },
+    createElement: () => textarea,
+    execCommand: () => false,
+  };
+
+  await assert.rejects(copyText('192.168.50.111', { documentRef }), /Copy failed/);
+  assert.equal(textarea.removed, true);
+});
+
+test('copy removes the temporary textarea when the fallback throws', async () => {
+  const textarea = {
+    style: {},
+    setAttribute() {},
+    select() {},
+    remove() { this.removed = true; },
+  };
+  const documentRef = {
+    body: { append() {} },
+    createElement: () => textarea,
+    execCommand: () => { throw new Error('legacy failed'); },
+  };
+
+  await assert.rejects(copyText('192.168.50.111', { documentRef }), /legacy failed/);
+  assert.equal(textarea.removed, true);
+});
+
 test('subscription usage combines traffic and caps progress', () => {
   assert.deepEqual(subscriptionUsage({ upload: 30, download: 80, total: 100, expire: 2 }), {
     upload: 30,