feat: enhance agent settlement features and improve data access controls

- Added new section in AGENTS.md detailing learned workspace facts for better understanding of settlement processes.
- Updated AgentNodeDestroyController to remove unnecessary checks for admin users.
- Enhanced AgentSettlement controllers to assert permissions for finance adjustments and bill operations.
- Improved query scopes in AgentSettlement services to ensure proper data access based on admin roles.
- Refactored methods in SettlementPartyEnrichment for better bill row enrichment and data handling.
- Introduced new methods in AdminAgentSettlementScope for managing agent node visibility and finance adjustments.

lang/zh/validation_business.php

@@ -31,6 +31,7 @@ return [
     'parent_overdue' => '上级代理存在逾期未结账单，禁止此操作。',
     'period_already_open' => '该时间范围的账期已在进行中，请直接关账，勿重复开期。',
     'period_site_has_open' => '本站已有进行中账期，请先关账后再开新账期。',
+    'period_overlaps_existing' => '账期时间与已有账期重叠，请调整起止日期。',
     'period_not_found' => '账期不存在或无权访问。',
     'period_already_closed' => '该账期已关账，请勿重复操作。',
     'share_snapshot_missing' => '账期内存在缺少占成快照的流水，无法关账。请先完成开奖结算或联系技术支持。',