feat: implement DLD (Deutschland Diplom) award

Add DOK-based award tracking with DCL confirmation. Counts unique
(DOK, band, mode) combinations toward the 100 DOK target.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

award-definitions/dld.json

@@ -0,0 +1,13 @@
+{
+  "id": "dld",
+  "name": "DLD",
+  "description": "Deutschland Diplom - Confirm 100 unique DOKs on different bands/modes",
+  "caption": "Contact and confirm stations with 100 unique DOKs (DARC Ortsverband Kennung) on different band/mode combinations. Each unique DOK on a unique band/mode counts as one point. Only DCL-confirmed QSOs with valid DOK information count toward this award.",
+  "category": "darc",
+  "rules": {
+    "type": "dok",
+    "target": 100,
+    "confirmationType": "dcl",
+    "displayField": "darcDok"
+  }
+}