feat(backend): add reconcile.run orchestrator with match + apply + CAS agg

backend/src/cyclone/reconcile.py

@@ -18,10 +18,12 @@ Match algorithm:
 from __future__ import annotations
 
 from dataclasses import dataclass
-from datetime import date
+from datetime import date, datetime, timezone
 from decimal import Decimal
 from typing import Iterable, Optional, Protocol
 
+from sqlalchemy import func
+
 from cyclone.db import ClaimState
 
 
@@ -206,3 +208,111 @@ def split_unmatched(
         [c for c in claims if c.id not in matched_claim_ids],
         [r for r in remits if r.id not in matched_remit_ids],
     )
+
+
+# --- reconcile.run() orchestrator ---------------------------------------------
+
+
+@dataclass
+class ReconcileResult:
+    matched: int = 0
+    unmatched_claims: int = 0
+    unmatched_remittances: int = 0
+    skipped: int = 0
+
+
+def run(session, batch_id: str) -> ReconcileResult:
+    """Orchestrate reconciliation for an 835 batch.
+
+    Expects Batch + Remittance + CasAdjustment rows already persisted
+    (this is called from store.add() AFTER commit). Loads the new
+    remittances + all currently-unmatched Claims, calls match(), then
+    applies each match's intent inside the caller's session.
+
+    Returns counts. Does NOT commit; caller controls transaction.
+    Raises on failure (caller catches and writes activity event).
+    """
+    from sqlalchemy import select
+    from cyclone.db import (
+        Batch, Claim, Remittance, CasAdjustment, Match, ActivityEvent,
+        ClaimState,
+    )
+
+    new_remits = list(
+        session.execute(
+            select(Remittance).where(Remittance.batch_id == batch_id)
+        ).scalars().all()
+    )
+
+    unmatched_claims = list(
+        session.execute(
+            select(Claim).where(Claim.matched_remittance_id.is_(None))
+        ).scalars().all()
+    )
+
+    matches = match(unmatched_claims, new_remits)
+
+    applied = 0
+    skipped = 0
+    for m in matches:
+        if m.is_reversal:
+            intent = apply_reversal(m.claim, m.remittance)
+        else:
+            intent = apply_payment(
+                m.claim, m.remittance,
+                charge=m.claim.charge_amount, paid=m.remittance.total_paid,
+                status_code=m.remittance.status_code,
+            )
+
+        if intent.skipped:
+            session.add(ActivityEvent(
+                ts=datetime.now(timezone.utc), kind=intent.activity_kind,
+                batch_id=batch_id, claim_id=m.claim.id,
+                remittance_id=m.remittance.id,
+                payload_json={"reason": intent.reason,
+                              "current_state": getattr(m.claim.state, "value", m.claim.state)},
+            ))
+            skipped += 1
+            continue
+
+        session.add(Match(
+            claim_id=m.claim.id, remittance_id=m.remittance.id,
+            strategy=m.strategy,
+            matched_at=datetime.now(timezone.utc),
+            prior_claim_state=intent.prior_claim_state,
+            is_reversal=m.is_reversal,
+        ))
+        if not m.is_reversal:
+            m.claim.state = intent.new_state
+        else:
+            m.claim.state = ClaimState.REVERSED
+        m.claim.matched_remittance_id = m.remittance.id
+
+        session.add(ActivityEvent(
+            ts=datetime.now(timezone.utc), kind=intent.activity_kind,
+            batch_id=batch_id, claim_id=m.claim.id,
+            remittance_id=m.remittance.id,
+            payload_json={"new_state": m.claim.state.value},
+        ))
+        applied += 1
+
+    # Aggregate CAS adjustments per Remittance.
+    for r in new_remits:
+        total = session.execute(
+            select(func.sum(CasAdjustment.amount))
+            .where(CasAdjustment.remittance_id == r.id)
+        ).scalar_one() or Decimal("0")
+        r.adjustment_amount = total
+
+    # Partition.
+    unmatched_claims_after, unmatched_remits_after = split_unmatched(
+        unmatched_claims, new_remits,
+        [m for m in matches if m.claim.id in {c.id for c in unmatched_claims}],
+    )
+
+    return ReconcileResult(
+        matched=applied,
+        unmatched_claims=len(unmatched_claims_after),
+        unmatched_remittances=len(unmatched_remits_after),
+        skipped=skipped,
+    )