Document first Azure AI evaluation runs and refine analysis prompt

samples/invoices-rejected-report.json

@@ -0,0 +1,12 @@
+{
+  "sourceBlob": "0c684ef3a1844dfaad0974eb8791ba29-invoices-invalid-structure.csv",
+  "checkedAtUtc": "2026-09-08T07:58:14.9845461+00:00",
+  "status": "Rejected",
+  "rows": [],
+  "fileErrors": [
+    "Zeile 3: Erwartet werden vier Spalten ohne Anf\u00FChrungszeichen."
+  ],
+  "totalCount": 0,
+  "validCount": 0,
+  "invalidCount": 0
+}