refactor: remove DXCC CW award and rename DXCC Mixed Mode to DXCC

- Removed dxcc-cw.json award definition
- Renamed "DXCC Mixed Mode" to "DXCC" in dxcc.json
- Changed award ID from "dxcc-mixed" to "dxcc"
- Removed dxcc-cw.json from awards service file list

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

award-definitions/dxcc-cw.json

@@ -1,27 +0,0 @@
-{
-  "id": "dxcc-cw",
-  "name": "DXCC CW",
-  "description": "Confirm 100 DXCC entities using CW mode",
-  "caption": "Contact and confirm 100 different DXCC entities using CW mode only. Only QSOs made with CW mode count toward this award. QSOs are confirmed when LoTW QSL is received.",
-  "category": "dxcc",
-  "rules": {
-    "target": 100,
-    "type": "filtered",
-    "baseRule": {
-      "type": "entity",
-      "entityType": "dxcc",
-      "target": 100,
-      "displayField": "entity"
-    },
-    "filters": {
-      "operator": "AND",
-      "filters": [
-        {
-          "field": "mode",
-          "operator": "eq",
-          "value": "CW"
-        }
-      ]
-    }
-  }
-}

award-definitions/dxcc.json

@@ -1,6 +1,6 @@
 {
-  "id": "dxcc-mixed",
-  "name": "DXCC Mixed Mode",
+  "id": "dxcc",
+  "name": "DXCC",
   "description": "Confirm 100 DXCC entities on any band/mode",
   "caption": "Contact and confirm 100 different DXCC entities. Any band and mode combination counts. QSOs are confirmed when LoTW QSL is received.",
   "category": "dxcc",