feat(backend): add GET /api/batches and GET /api/batches/{id}

backend/src/cyclone/api.py

@@ -369,4 +369,52 @@ def _ndjson_stream_835(result: ParseResult835) -> Iterator[bytes]:
     yield (json.dumps({"type": "summary", "data": json.loads(result.summary.model_dump_json())}) + "\n").encode("utf-8")
 
 
+# --------------------------------------------------------------------------- #
+# GET endpoints (read views over the in-memory store)
+# --------------------------------------------------------------------------- #
+
+
+def _batch_summary_claim_count(rec: BatchRecord) -> int:
+    """Return the number of claims on a batch, handling both 837P and 835."""
+    if rec.kind == "837p":
+        return len(rec.result.claims)  # type: ignore[attr-defined]
+    if rec.kind == "835":
+        return len(rec.result.claims)  # type: ignore[attr-defined]
+    return 0
+
+
+@app.get("/api/batches")
+def list_batches(limit: int = Query(100, ge=1, le=1000)) -> dict[str, Any]:
+    """Summary of all parsed batches, newest first."""
+    records = store.list(limit=limit)
+    items = [
+        {
+            "id": r.id,
+            "kind": r.kind,
+            "inputFilename": r.input_filename,
+            "parsedAt": r.parsed_at.isoformat().replace("+00:00", "Z"),
+            "claimCount": _batch_summary_claim_count(r),
+        }
+        for r in records
+    ]
+    all_records = store.all()
+    return {
+        "items": items,
+        "total": len(all_records),
+        "returned": len(items),
+        "has_more": len(all_records) > len(items),
+    }
+
+
+@app.get("/api/batches/{batch_id}")
+def get_batch(batch_id: str) -> Any:
+    rec = store.get(batch_id)
+    if rec is None:
+        raise HTTPException(
+            status_code=404,
+            detail={"error": "Not found", "detail": f"Batch {batch_id} not found"},
+        )
+    return json.loads(rec.result.model_dump_json())
+
+
 __all__ = ["app"]