feat(sp7): LineReconciliation ORM model

backend/src/cyclone/db.py

@@ -342,6 +342,49 @@ class ServiceLinePayment(Base):
     )
 
 
+class LineReconciliation(Base):
+    """One row per matched (or explicitly unmatched) 837 service line within a claim.
+
+    SP7. Created during ``reconcile.run()`` after the claim↔remit match.
+    At least one of ``claim_service_line_id`` / ``service_line_payment_id``
+    must be non-null; the application enforces this.
+
+    See spec §3.2.
+    """
+    __tablename__ = "line_reconciliations"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    claim_id: Mapped[str] = mapped_column(
+        String(64), ForeignKey("claims.id", ondelete="CASCADE"), nullable=False
+    )
+    claim_service_line_id: Mapped[Optional[int]] = mapped_column(
+        Integer,
+        ForeignKey("service_lines.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    service_line_payment_id: Mapped[Optional[int]] = mapped_column(
+        Integer,
+        ForeignKey("service_line_payments.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    status: Mapped[str] = mapped_column(String(16), nullable=False)
+    match_score: Mapped[Optional[int]] = mapped_column(Integer, nullable=True)
+    reconciled_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False
+    )
+
+    __table_args__ = (
+        Index("ix_line_reconciliations_claim_id", "claim_id"),
+        Index(
+            "ix_line_reconciliations_claim_service_line_id", "claim_service_line_id"
+        ),
+        Index(
+            "ix_line_reconciliations_service_line_payment_id",
+            "service_line_payment_id",
+        ),
+    )
+
+
 class Match(Base):
     __tablename__ = "matches"