feat(calc): 单笔回款核算引擎与绩效台账

- calc_service.calc_receipt：锁回款行→settlement_status=0 校验→发货批次/
  归属前置→resolve_snapshot(回款日)→按 calc_template 分派（与 _preview_rate
  同构，‰÷1000 防线）→items 行级折算（行类别阈值，混合按行汇总）→
  barter/起付/R→台账 v1→CAS 置已核算，单 audit 事务
- 策略点集中：_personal_rate（#12 经理个人户单笔落 0 待答复）、_row_profit
  （#20 不含税原样）；核算粒度 #25 一期口径=业务级一次性计提（重复回款
  repeated=True 仅登记进度）
- 台账仓储：生效行查询/业务级判定/版本号；schemas LedgerOut/Query
- api /api/v1/calc/*：台账分页/详情/核算触发（写限 admin+marketing_ops）
- 测试 8 例：金标准双类别复算到分（DB 锚定 4000.00/39.11/39.11）、
  一次性计提、已核算 400、未指定批次、成本缺失行保守 -3000、负绩效照算、
  准入、列表筛选；行级明细折算两位固化
- conftest 清理顺序修正：V7 台账/月结清理移到回款/人员删除之前
  （RESTRICT 外键不挡序）

Co-Authored-By: Claude Code <noreply@anthropic.com>

backend/app/repositories/performance_ledger_repository.py

@@ -0,0 +1,114 @@
+"""绩效核算台账仓储：只读写数据并 flush；commit/rollback 在服务层。"""
+
+from sqlalchemy import func, select
+from sqlalchemy.orm import Session
+
+from app.models import PerformanceLedger
+from app.schemas.calc import LedgerQuery
+
+
+def get_by_id(session: Session, ledger_id: int) -> PerformanceLedger | None:
+    """按主键取台账行。"""
+    return session.get(PerformanceLedger, ledger_id)
+
+
+def get_active_by_receipt(
+    session: Session, receipt_id: int, *, calc_type: int = 1
+) -> PerformanceLedger | None:
+    """取某回款的当前生效核算行（is_active=1；无则 None）。"""
+    return session.execute(
+        select(PerformanceLedger).where(
+            PerformanceLedger.receipt_id == receipt_id,
+            PerformanceLedger.calc_type == calc_type,
+            PerformanceLedger.is_active == 1,
+        )
+    ).scalar_one_or_none()
+
+
+def has_active_for_business(session: Session, business_id: int, *, calc_type: int = 1) -> bool:
+    """该业务是否已有生效核算行（核算粒度 #25：业务级一次性计提的判定）。"""
+    return (
+        session.execute(
+            select(func.count())
+            .select_from(PerformanceLedger)
+            .where(
+                PerformanceLedger.business_id == business_id,
+                PerformanceLedger.calc_type == calc_type,
+                PerformanceLedger.is_active == 1,
+            )
+        ).scalar_one()
+        > 0
+    )
+
+
+def get_active_by_receipt_of_business(
+    session: Session, business_id: int, *, calc_type: int = 1
+) -> PerformanceLedger:
+    """取该业务当前生效的核算行（重复回款登记进度时回显既有台账）。"""
+    return (
+        session.execute(
+            select(PerformanceLedger)
+            .where(
+                PerformanceLedger.business_id == business_id,
+                PerformanceLedger.calc_type == calc_type,
+                PerformanceLedger.is_active == 1,
+            )
+            .order_by(PerformanceLedger.id.desc())
+        )
+        .scalars()
+        .first()
+    )
+
+
+def add(session: Session, row: PerformanceLedger) -> PerformanceLedger:
+    """落台账行（flush 取 id；commit 在服务层）。"""
+    session.add(row)
+    session.flush()
+    return row
+
+
+def mark_inactive(session: Session, row: PerformanceLedger) -> None:
+    """重算时把旧版本行翻为已替代（全表唯一的受控 UPDATE 例外；不 commit）。"""
+    row.is_active = 0
+    session.flush()
+
+
+def next_version(session: Session, receipt_id: int) -> int:
+    """某回款的下一个核算版本号（max+1；无行则 1）。"""
+    current = session.execute(
+        select(func.max(PerformanceLedger.calc_version)).where(
+            PerformanceLedger.receipt_id == receipt_id
+        )
+    ).scalar_one()
+    return int(current) + 1
+
+
+def list_ledger(session: Session, query: LedgerQuery) -> list[PerformanceLedger]:
+    """分页查询台账（筛选：月/人员/业务/生效/类型）。"""
+    stmt = select(PerformanceLedger).where(*_filters(query))
+    stmt = stmt.order_by(PerformanceLedger.id.desc()).offset(query.offset).limit(query.page_size)
+    return list(session.execute(stmt).scalars())
+
+
+def count_ledger(session: Session, query: LedgerQuery) -> int:
+    """台账计数（与 list_ledger 同筛选）。"""
+    return int(
+        session.execute(
+            select(func.count()).select_from(PerformanceLedger).where(*_filters(query))
+        ).scalar_one()
+    )
+
+
+def _filters(query: LedgerQuery) -> tuple:
+    filters = []
+    if query.settlement_month:
+        filters.append(PerformanceLedger.settlement_month == query.settlement_month)
+    if query.personnel_id is not None:
+        filters.append(PerformanceLedger.personnel_id == query.personnel_id)
+    if query.business_id is not None:
+        filters.append(PerformanceLedger.business_id == query.business_id)
+    if query.is_active is not None:
+        filters.append(PerformanceLedger.is_active == query.is_active)
+    if query.calc_type is not None:
+        filters.append(PerformanceLedger.calc_type == query.calc_type)
+    return tuple(filters)