fix: 部分收付累计释额并扩展结算 E2E 与 CI

账期收付改为按累计已付同步 credit_ledger，修复多笔 partial_paid 与坏账核销重复释额；新增 API E2E（占成、权限、部分收付/坏账）与 GitHub Actions e2e-api job。

Co-authored-by: Cursor <cursoragent@cursor.com>

e2e/tests/api/10.agent-settlement.spec.ts

@@ -8,6 +8,7 @@ import {
   adminCtxOf,
   fetchOpenDrawNo,
   playerLoginViaBypass,
+  openSettlementPeriod,
   setupCreditPlayer,
 } from './_helper';
 import { runWalletDrawSettlement } from './helpers/draw-settlement';
@@ -20,21 +21,7 @@ test('信用下注结算后关账 → 生成玩家 settlement_bill', async () =>
 
   const adminSession = await adminLoginViaBypass();
   const admin = await adminCtxOf(adminSession.accessToken);
-
-  const start = new Date(Date.now() - 3600_000).toISOString().replace('T', ' ').slice(0, 19);
-  const end = new Date(Date.now() + 3600_000).toISOString().replace('T', ' ').slice(0, 19);
-
-  const open = await admin.post('/api/v1/admin/settlement-periods', {
-    data: {
-      admin_site_id: credit.admin_site_id,
-      period_start: start,
-      period_end: end,
-    },
-  });
-  expect(open.ok(), `open period status=${open.status()}`).toBeTruthy();
-  const openBody = (await open.json()) as any;
-  expect(openBody.code).toBe(0);
-  const periodId = openBody.data.id;
+  const periodId = await openSettlementPeriod(admin, credit.admin_site_id, credit.site_code);
 
   const playerSession = await playerLoginViaBypass({
     site_code: credit.site_code,