feat(sp7): ServiceLinePayment ORM model

backend/src/cyclone/db.py

@@ -300,6 +300,48 @@ class CasAdjustment(Base):
     )
 
 
+class ServiceLinePayment(Base):
+    """One row per 835 SVC composite (loop 2110).
+
+    SP7. Persisted on 835 ingest *before* ``reconcile.run()`` decides
+    which claim this line applies to. Independent of claim matching.
+
+    See spec §3.1.
+    """
+    __tablename__ = "service_line_payments"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    remittance_id: Mapped[str] = mapped_column(
+        String(64), ForeignKey("remittances.id", ondelete="CASCADE"), nullable=False
+    )
+    line_number: Mapped[int] = mapped_column(Integer, nullable=False)
+    procedure_qualifier: Mapped[str] = mapped_column(String(4), nullable=False)
+    procedure_code: Mapped[str] = mapped_column(String(16), nullable=False)
+    modifiers_json: Mapped[str] = mapped_column(
+        JSONText, nullable=False, default=lambda: "[]"
+    )
+    charge: Mapped[Decimal] = mapped_column(Numeric(12, 2), nullable=False)
+    payment: Mapped[Decimal] = mapped_column(Numeric(12, 2), nullable=False)
+    units: Mapped[Optional[Decimal]] = mapped_column(Numeric(10, 2), nullable=True)
+    unit_type: Mapped[Optional[str]] = mapped_column(String(8), nullable=True)
+    service_date: Mapped[Optional[date]] = mapped_column(Date, nullable=True)
+    ref_benefit_plan: Mapped[Optional[str]] = mapped_column(String(64), nullable=True)
+    superseded_by_id: Mapped[Optional[int]] = mapped_column(
+        Integer,
+        ForeignKey("service_line_payments.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+
+    __table_args__ = (
+        Index("ix_service_line_payments_remittance_id", "remittance_id"),
+        Index(
+            "ix_service_line_payments_procedure_code_date",
+            "procedure_code",
+            "service_date",
+        ),
+    )
+
+
 class Match(Base):
     __tablename__ = "matches"