feat: add 73 on 73 satellite award

Add new award for confirming 73 unique QSO partners via AO-73 satellite.
Counts unique callsigns confirmed via LoTW with satName filter.

Co-Authored-By: Claude <noreply@anthropic.com>

award-definitions/73-on-73.json

@@ -0,0 +1,23 @@
+{
+  "id": "73-on-73",
+  "name": "73 on 73",
+  "description": "Confirm 73 unique QSO partners on satellite AO-73",
+  "caption": "Contact and confirm 73 different stations (unique callsigns) via the AO-73 satellite. Each unique callsign confirmed via LoTW counts toward the total of 73.",
+  "category": "satellite",
+  "rules": {
+    "type": "entity",
+    "entityType": "callsign",
+    "target": 73,
+    "displayField": "callsign",
+    "filters": {
+      "operator": "AND",
+      "filters": [
+        {
+          "field": "satName",
+          "operator": "eq",
+          "value": "AO-73"
+        }
+      ]
+    }
+  }
+}