支持财务经办与公司代表关联方还款确认（09-17-company-loan-principal-repayment）

公司只有财务和出借收款经理两名办理人，新增限定公司、出借人和借款范围的关联方确认模式。
仅豁免指定公司代表的收款人关联；经办、自审、证据、交易归属、资金占用及 Q6 限制保留。
贯通付款、人工回单、银行对账、补证恢复、晚到补记与追回；电脑和手机显示实际确认身份。
授权版本、付款与对账停用事件及历史决定只增不改，新增迁移 20261009010000_loan_related_approval。

本地合成验证：82 迁移、HTTP 109 组、浏览器 33 组、数据库约束 9 组通过；13 个有效资金守卫变异均捕获。
已有服务端全量 4519 项通过、1 项原有跳过，后续定向 77 项通过；提示收尾另有 908 项合同测试及前端构建通过。
按用户授权提交后对干净候选运行正式 verify-candidate，不沿用旧候选回执。

限制：独立代码复核待完成（inline 模式）；真实回单待验。本次仅本地提交，不推送、不部署。
生成关联决定后不能直接降回不理解该模式的旧代码；真实授权、录入、生产核实和付款仍须明确批准。

server/prisma/schema.prisma

@@ -1951,6 +1951,9 @@ model EntityRiskFlag {
 }
 
 model PaymentBatch {
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   loan_repayment_id String? @db.Uuid
   loan_repayment LoanRepayment? @relation(fields: [loan_repayment_id], references: [id], onDelete: Restrict)
   id                       String                 @id @default(uuid()) @db.Uuid
@@ -2097,6 +2100,9 @@ model PaymentReceiptVerification {
 }
 
 model PaymentReceiptManualProposal {
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   id String @id @default(uuid()) @db.Uuid
   attachment_id String @db.Uuid
   original_verification_id String @db.Uuid
@@ -3879,6 +3885,56 @@ model ApprovalTransfer {
 }
 
 
+// Scoped company authority for related-party loan repayment. Content and events
+// are immutable; a newer confirmed version supersedes earlier scope, never
+// falling back to an older version after stopping either permission.
+model LoanRelatedAuthorization {
+  id                 String   @id @default(uuid()) @db.Uuid
+  legal_entity_id    String   @db.Uuid
+  lender_id          String   @db.Uuid
+  approver_id        String   @db.Uuid
+  identity_version   Int
+  version            Int
+  basis              String   @db.VarChar(1000)
+  proposed_by        String   @db.Uuid
+  proposed_at        DateTime @default(now())
+  request_key        String   @db.Uuid
+
+  loans  LoanRelatedAuthorizationLoan[]
+  events LoanRelatedAuthorizationEvent[]
+
+  @@unique([lender_id, version])
+  @@unique([proposed_by, request_key])
+  @@map("loan_related_authorizations")
+}
+
+model LoanRelatedAuthorizationLoan {
+  authorization_id String @db.Uuid
+  loan_id          String @db.Uuid
+
+  authorization LoanRelatedAuthorization @relation(fields: [authorization_id], references: [id], onDelete: Restrict)
+
+  @@id([authorization_id, loan_id])
+  @@map("loan_related_authorization_loans")
+}
+
+model LoanRelatedAuthorizationEvent {
+  id               String   @id @default(uuid()) @db.Uuid
+  authorization_id String   @db.Uuid
+  sequence         Int
+  action           String   @db.VarChar(24)
+  payment_enabled  Boolean
+  reconcile_enabled Boolean
+  actor_id         String   @db.Uuid
+  reason           String   @db.VarChar(500)
+  created_at       DateTime @default(now())
+
+  authorization LoanRelatedAuthorization @relation(fields: [authorization_id], references: [id], onDelete: Restrict)
+
+  @@unique([authorization_id, sequence])
+  @@map("loan_related_authorization_events")
+}
+
 model LoanLender {
   id                     String   @id @default(uuid()) @db.Uuid
   legal_entity_id        String   @db.Uuid
@@ -3950,6 +4006,12 @@ model CompanyLoan {
 }
 
 model LoanRepayment {
+  approval_mode              String  @default("independent") @db.VarChar(16)
+  authorization_id           String? @db.Uuid
+  approval_context           Json?
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   id                      String   @id @default(uuid()) @db.Uuid
   repayment_no            String   @unique @db.VarChar(64)
   legal_entity_id         String   @db.Uuid
@@ -4025,6 +4087,9 @@ model LoanEvidence {
 // Partial unique index (one proposed/approved per batch) and history trigger
 // live in migration 20261006010000_loan_receipt_attribution.
 model LoanReceiptAttribution {
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   id                   String    @id @default(uuid()) @db.Uuid
   payment_batch_id     String    @db.Uuid
   fingerprint          String    @db.VarChar(64)
@@ -4113,6 +4178,9 @@ model LoanBankSubmission {
 }
 
 model LoanBankSubmissionAttestation {
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   id               String    @id @default(uuid()) @db.Uuid
   payment_batch_id String    @db.Uuid
   submission_ids   Json
@@ -4162,6 +4230,9 @@ model LoanBankTerminalEvidence {
 }
 
 model LoanBankTerminalFact {
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   id                      String    @id @default(uuid()) @db.Uuid
   payment_batch_id        String    @db.Uuid
   submission_id           String    @db.Uuid
@@ -4207,6 +4278,9 @@ model LoanFailureEvidenceUse {
 
 // SR: original bank conclusions remain immutable; recovery controls release only.
 model LoanReleaseRecovery {
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   id String @id @default(uuid()) @db.Uuid
   payment_batch_id String @db.Uuid
   sequence Int
@@ -4311,6 +4385,9 @@ model LoanFreezeReason {
 }
 
 model LoanBankResultEvent {
+  loan_approval_mode          String  @default("independent") @db.VarChar(16)
+  loan_authorization_id       String? @db.Uuid
+  loan_approval_context       Json?
   id String @id @default(uuid()) @db.Uuid
   payment_batch_id String @db.Uuid
   kind String @db.VarChar(16)