meta: enrich gold_512_npy_bin4/meta.json with corrected voltage 300 kV, probe, CL, source

4dstem/gold_512_npy_bin4/meta.json

@@ -35,6 +35,11 @@
     0.46,
     0.46
   ],
-  "source": "bobleesj/quantem-data 4dstem/gold_512",
-  "purpose": "workshop / Colab demo - full real-space, detector-only bin"
+  "source": "Arina 4D-STEM master /home/owner/ssd/data/bob/20260423_gold_drift_v6_4dstem_pair/gold_004_master.h5 (drift-pair acquisition; sibling session 20260408_gold_4dstem_512_ssb/dataset.yaml supplies optics)",
+  "purpose": "workshop / Colab demo - full real-space, detector-only bin",
+  "voltage_kV": 300,
+  "camera_length_mm": 91,
+  "probe_semiangle_mrad": 30,
+  "mag_MX": null,
+  "rotation_deg": 0.0
 }