docs: add DLD (Deutschland Diplom) award documentation

Add comprehensive documentation for the DLD award including:
- Award definition and JSON structure
- Progress calculation logic
- DOK entity type and DARC category
- Example DOKs and confirmation details
- DCL resources and references

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

docs/DOCUMENTATION.md

@@ -131,7 +131,8 @@ Defines the database structure using Drizzle ORM schema builder.
 - Award progress calculation
 - Entity breakdown by band/mode
 - Confirmation status tracking (LoTW, DCL)
-- DXCC, WAS, VUCC award support
+- DXCC, WAS, VUCC, DLD award support
+- DOK-based award calculation with DCL confirmation
 
 **Job Queue Service** (`src/backend/services/job-queue.service.js`)
 - Background job management
@@ -194,7 +195,9 @@ award/
 │   ├── dxcc-cw.json           # DXCC CW-specific award
 │   ├── was.json               # WAS award configurations
 │   ├── vucc-sat.json          # VUCC Satellite award
-│   └── sat-rs44.json          # Satellite RS-44 award
+│   ├── sat-rs44.json          # Satellite RS-44 award
+│   ├── special-stations.json  # Special event stations award
+│   └── dld.json               # DLD (Deutschland Diplom) award
 │
 ├── drizzle/                   # Database migrations
 │   └── 0000_init.sql         # Initial schema
@@ -288,8 +291,12 @@ award/
   county: text
   satName: text (satellite name)
   satMode: text (satellite mode)
+  myDarcDok: text (user's DOK - DARC Ortsverband Kennung)
+  darcDok: text (QSO partner's DOK)
   lotwQslRdate: text (LoTW confirmation date)
   lotwQslRstatus: text ('Y', 'N', '?')
+  dclQslRdate: text (DCL confirmation date)
+  dclQslRstatus: text ('Y', 'N', '?')
   lotwSyncedAt: timestamp
   createdAt: timestamp
 }
@@ -361,6 +368,7 @@ Each award is defined with the following structure:
 | `dxcc` | DXCC entities (countries) | `entityId` |
 | `state` | US States, Canadian provinces | `state` |
 | `grid` | Maidenhead grid squares | `grid` |
+| `dok` | DARC Ortsverband Kennung (German local clubs) | `darcDok` |
 
 ### Filter Operators
 
@@ -380,6 +388,7 @@ Each award is defined with the following structure:
 - **`was`**: Worked All States awards
 - **`vucc`**: VHF/UHF Century Club awards
 - **`satellite`**: Satellite-specific awards
+- **`darc`**: DARC (German Amateur Radio Club) awards
 
 ---
 
@@ -603,6 +612,55 @@ confirmed = COUNT(DISTINCT callsign
 
 ---
 
+### 6. DLD (Deutschland Diplom)
+
+**File**: `award-definitions/dld.json`
+
+```json
+{
+  "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"
+  }
+}
+```
+
+**Explanation:**
+- Counts unique (DOK, band, mode) combinations
+- Only QSOs with valid `darcDok` values are counted
+- Only DCL-confirmed QSOs (`dclQslRstatus = 'Y'`) count toward the award
+- Target: 100 unique DOKs on different band/mode combinations
+- Each unique DOK on a unique band/mode combination counts as one point
+- Example: Working DOK F03 on 20m CW and 40m SSB counts as 2 points
+
+**Progress Calculation:**
+```javascript
+worked = COUNT(DISTINCT darcDok
+         WHERE darcDok IS NOT NULL)
+confirmed = COUNT(DISTINCT darcDok
+           WHERE darcDok IS NOT NULL AND dclQslRstatus = 'Y')
+```
+
+**Example DOKs:**
+- `"F03"` - Ortsverband Frankfurt am Main
+- `"P30"` - Ortsverband München
+- `"G20"` - Ortsverband Köln
+- DOKs consist of a letter (district) and two digits (local club)
+
+**Confirmation:**
+- Only DCL (DARC Community Logbook) confirmations count
+- LoTW confirmations do not count toward this award
+- This is a DARC-specific award using DARC's confirmation system
+
+---
+
 ### Advanced Filter Examples
 
 #### Multiple Conditions (AND)
@@ -776,6 +834,7 @@ The award system is designed for extensibility. Planned enhancements:
    - CQ Zones
    - ITU Zones
    - Counties
+   - DOK (German DARC Ortsverband Kennung) ✓ **Implemented**
 
 2. **Advanced Filters**:
    - Date ranges
@@ -812,7 +871,9 @@ When adding new awards or modifying the award system:
 ## Resources
 
 - [ARRL LoTW](https://lotw.arrl.org/)
+- [DARC Community Logbook (DCL)](https://dcl.darc.de/)
 - [ADIF Specification](https://adif.org/)
 - [DXCC List](https://www.arrl.org/dxcc)
 - [VUCC Program](https://www.arrl.org/vucc)
 - [WAS Award](https://www.arrl.org/was)
+- [DLD Award](https://www.darc.de/der-club/referate/conteste/dld/)