fix: invalidate caches after deleting QSOs

After deleting all QSOs, invalidate the stats and user caches so the
QSO page shows updated statistics instead of stale cached data.

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

src/backend/index.js

@@ -867,6 +867,7 @@ const app = new Elysia()
         message: `Deleted ${deleted} QSO(s)`,
       };
     } catch (error) {
+      logger.error('Failed to delete QSOs', { error: error.message, stack: error.stack });
       set.status = 500;
       return {
         success: false,

src/backend/services/lotw.service.js

@@ -1,5 +1,5 @@
 import { db, logger } from '../config.js';
-import { qsos, qsoChanges } from '../db/schema/index.js';
+import { qsos, qsoChanges, syncJobs, awardProgress } from '../db/schema/index.js';
 import { max, sql, eq, and, or, desc, like } from 'drizzle-orm';
 import { updateJobProgress } from './job-queue.service.js';
 import { parseADIF, normalizeBand, normalizeMode } from '../utils/adif-parser.js';
@@ -609,10 +609,58 @@ export async function getLastLoTWQSLDate(userId) {
 
 /**
  * Delete all QSOs for a user
+ * Also deletes related qso_changes records to satisfy foreign key constraints
  */
 export async function deleteQSOs(userId) {
+  logger.debug('Deleting all QSOs for user', { userId });
+
+  // Step 1: Delete qso_changes that reference QSOs for this user
+  // Need to use a subquery since qso_changes doesn't have userId directly
+  const qsoIdsResult = await db
+    .select({ id: qsos.id })
+    .from(qsos)
+    .where(eq(qsos.userId, userId));
+
+  const qsoIds = qsoIdsResult.map(r => r.id);
+
+  let deletedChanges = 0;
+  if (qsoIds.length > 0) {
+    // Delete qso_changes where qsoId is in the list of QSO IDs
+    const changesResult = await db
+      .delete(qsoChanges)
+      .where(sql`${qsoChanges.qsoId} IN ${sql.raw(`(${qsoIds.join(',')})`)}`);
+
+    deletedChanges = changesResult.changes || changesResult || 0;
+    logger.debug('Deleted qso_changes', { count: deletedChanges });
+  }
+
+  // Step 2: Delete the QSOs
   const result = await db.delete(qsos).where(eq(qsos.userId, userId));
-  return result;
+  logger.debug('Delete result', { result, type: typeof result, keys: Object.keys(result || {}) });
+
+  // Drizzle with SQLite/bun:sqlite returns various formats depending on driver
+  let count = 0;
+  if (result) {
+    if (typeof result === 'number') {
+      count = result;
+    } else if (result.changes !== undefined) {
+      count = result.changes;
+    } else if (result.rows !== undefined) {
+      count = result.rows;
+    } else if (result.meta?.changes !== undefined) {
+      count = result.meta.changes;
+    } else if (result.meta?.rows !== undefined) {
+      count = result.meta.rows;
+    }
+  }
+
+  logger.info('Deleted QSOs', { userId, count, deletedChanges });
+
+  // Invalidate caches for this user
+  await invalidateStatsCache(userId);
+  await invalidateUserCache(userId);
+
+  return count;
 }
 
 /**