fix(phone-sms): 补回 NexSMS provider registry 接入

补回 NexSMS provider adapter，并在 background 与 sidepanel 加载。
同时补充 registry 创建真实 NexSMS provider 的测试，避免后续回归。

tests/phone-sms-provider-registry.test.js

@@ -3,6 +3,8 @@ const assert = require('node:assert/strict');
 const fs = require('node:fs');
 
 const source = fs.readFileSync('phone-sms/providers/registry.js', 'utf8');
+const maDaoSource = fs.readFileSync('phone-sms/providers/madao.js', 'utf8');
+const nexSmsSource = fs.readFileSync('phone-sms/providers/nexsms.js', 'utf8');
 
 function loadRegistry(root = {}) {
   return new Function('self', `${source}; return self.PhoneSmsProviderRegistry;`)(root);
@@ -16,6 +18,9 @@ test('phone sms provider registry normalizes ids, order and labels consistently'
     PhoneSmsFiveSimProvider: {
       createProvider: (deps = {}) => ({ provider: '5sim', deps }),
     },
+    PhoneSmsNexSmsProvider: {
+      createProvider: (deps = {}) => ({ provider: 'nexsms', deps }),
+    },
     PhoneSmsMaDaoProvider: {
       createProvider: (deps = {}) => ({ provider: 'madao', deps }),
     },
@@ -52,5 +57,43 @@ test('phone sms provider registry normalizes ids, order and labels consistently'
     registry.createProvider('madao', { foo: 2 }),
     { provider: 'madao', deps: { foo: 2 } }
   );
-  assert.throws(() => registry.createProvider('nexsms'), /接码平台模块未加载：nexsms/);
+  assert.deepStrictEqual(
+    registry.createProvider('nexsms', { foo: 3 }),
+    { provider: 'nexsms', deps: { foo: 3 } }
+  );
+});
+
+test('phone sms provider registry can create the real MaDao provider module', () => {
+  const maDaoModule = new Function('self', `${maDaoSource}; return self.PhoneSmsMaDaoProvider;`)({});
+  const registry = loadRegistry({
+    PhoneSmsMaDaoProvider: maDaoModule,
+  });
+
+  const provider = registry.createProvider('madao', { fetchImpl: 'demo-fetch' });
+
+  assert.equal(provider.id, 'madao');
+  assert.equal(provider.label, 'MaDao');
+  assert.equal(provider.defaultProduct, 'openai');
+  assert.equal(typeof provider.acquireActivation, 'function');
+  assert.equal(typeof provider.pollActivation, 'function');
+  assert.equal(typeof provider.releaseActivation, 'function');
+  assert.equal(provider.mapTicketStatus('waiting_code'), 'waiting_code');
+});
+
+test('phone sms provider registry can create the real NexSMS provider module', () => {
+  const nexSmsModule = new Function('self', `${nexSmsSource}; return self.PhoneSmsNexSmsProvider;`)({});
+  const registry = loadRegistry({
+    PhoneSmsNexSmsProvider: nexSmsModule,
+  });
+
+  const provider = registry.createProvider('nexsms', { fetchImpl: 'demo-fetch' });
+
+  assert.equal(provider.id, 'nexsms');
+  assert.equal(provider.label, 'NexSMS');
+  assert.equal(provider.defaultProduct, 'OpenAI');
+  assert.equal(provider.defaultServiceCode, 'ot');
+  assert.equal(typeof provider.fetchBalance, 'function');
+  assert.equal(typeof provider.fetchPrices, 'function');
+  assert.equal(provider.normalizeCountryId('8'), 8);
+  assert.equal(provider.normalizeServiceCode(' OT '), 'ot');
 });