fix: deduplicate synthetic quality exclusions

scripts/ai-kpi.test.mjs

@@ -5,6 +5,12 @@ const moduleUrl = new URL('./ai-kpi.mjs', import.meta.url);
 import { spawnSync } from 'node:child_process';
 import * as api from './ai-kpi.mjs';
 const fixture = () => JSON.parse(readFileSync(new URL('./fixtures/ai-kpi-synthetic.json', import.meta.url)));
+test('semantic change duplicates preserve the complete quality report including exclusions', () => {
+  const original = fixture();
+  const repeated = fixture();
+  repeated.changes.push({...repeated.changes[0]});
+  assert.deepEqual(api.calculate(repeated).kpis['escaped-quality-rate'], api.calculate(original).kpis['escaped-quality-rate']);
+});
 test('CLI report exposes implemented KPI contracts and explicit omissions', async () => {
   const m = await import(moduleUrl);
   assert.equal(typeof m.calculate, 'function');