fix: use qsoId for fetching QSO details in award page modal

The award page was filtering QSOs by callsign/date/band/mode, which
could return the wrong QSO when multiple QSOs with the same callsign
exist on the same band/mode combination.

Changes:
- Backend: Add qsoId field to award entity breakdown responses
- Backend: Add GET /api/qsos/:id endpoint to fetch QSO by ID
- Backend: Implement getQSOById() function in lotw.service.js
- Frontend: Update openQSODetailModal() to fetch by qsoId instead of filtering
- Frontend: Include qsoId in QSO entry objects for modal click handler

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

src/backend/index.js

@@ -13,6 +13,7 @@ import {
   getUserQSOs,
   getQSOStats,
   deleteQSOs,
+  getQSOById,
 } from './services/lotw.service.js';
 import {
   enqueueJob,
@@ -489,6 +490,44 @@ const app = new Elysia()
     }
   })
 
+  /**
+   * GET /api/qsos/:id
+   * Get a single QSO by ID (requires authentication)
+   */
+  .get('/api/qsos/:id', async ({ user, params, set }) => {
+    if (!user) {
+      set.status = 401;
+      return { success: false, error: 'Unauthorized' };
+    }
+
+    try {
+      const qsoId = parseInt(params.id);
+      if (isNaN(qsoId)) {
+        set.status = 400;
+        return { success: false, error: 'Invalid QSO ID' };
+      }
+
+      const qso = await getQSOById(user.id, qsoId);
+
+      if (!qso) {
+        set.status = 404;
+        return { success: false, error: 'QSO not found' };
+      }
+
+      return {
+        success: true,
+        qso,
+      };
+    } catch (error) {
+      logger.error('Failed to fetch QSO by ID', { error: error.message, userId: user?.id, qsoId: params.id });
+      set.status = 500;
+      return {
+        success: false,
+        error: 'Failed to fetch QSO',
+      };
+    }
+  })
+
   /**
    * GET /api/qsos/stats
    * Get QSO statistics (requires authentication)