Introduce stable server IDs for subscription state

test/server/state-store.test.js

@@ -9,6 +9,7 @@ import {
   createStateStore,
   STATE_SCHEMA_VERSION,
 } from '../../src/server/services/stateStore.js';
+import { createServerId } from '../../src/shared/serverIdentity.js';
 
 const fixture = (t) => {
   const directory = fs.mkdtempSync(path.join(os.tmpdir(), 'harbor-state-store-'));
@@ -39,7 +40,7 @@ test('schema v2 state migrates built-in .ru into a normal enabled rule', (t) =>
     schemaVersion: 2,
     revision: 7,
     selectedTag: 'nl',
-    servers: [{ tag: 'nl' }],
+    servers: [{ tag: 'nl', type: 'vless', server: 'nl.example', server_port: 443 }],
   };
   fs.writeFileSync(filePath, JSON.stringify(legacy));
 
@@ -53,11 +54,31 @@ test('schema v2 state migrates built-in .ru into a normal enabled rule', (t) =>
     { type: 'domain_suffix', value: 'ru', enabled: true },
   ]);
   assert.equal(migrated.appliedTag, 'nl');
+  assert.equal(migrated.selectedServerId, createServerId(legacy.servers[0]));
+  assert.equal(migrated.appliedServerId, migrated.selectedServerId);
   assert.equal(store.migration.fromVersion, 2);
   assert.deepEqual(JSON.parse(fs.readFileSync(store.migration.backupPath, 'utf8')), legacy);
   assert.equal(JSON.parse(fs.readFileSync(filePath, 'utf8')).schemaVersion, STATE_SCHEMA_VERSION);
 });
 
+test('ambiguous legacy selectedTag explicitly requires a new choice', (t) => {
+  const filePath = fixture(t);
+  fs.writeFileSync(filePath, JSON.stringify({
+    schemaVersion: 3,
+    selectedTag: 'Amsterdam',
+    servers: [
+      { tag: 'Amsterdam', type: 'vless', server: 'nl-1.example', server_port: 443 },
+      { tag: 'Amsterdam', type: 'vless', server: 'nl-2.example', server_port: 443 },
+    ],
+  }));
+
+  const migrated = createStateStore(filePath).read();
+
+  assert.equal(migrated.selectedServerId, '');
+  assert.equal(migrated.appliedServerId, '');
+  assert.equal(migrated.servers.length, 2);
+});
+
 test('corrupt JSON is preserved and replaced with an explicit recovery state', (t) => {
   const filePath = fixture(t);
   fs.writeFileSync(filePath, '{broken');