feat: per-app telemetry reset button on app detail page

Adds "Telemetria törlése" button that deletes all telemetry records and
known issues for a specific app. Useful after major app updates when old
data is no longer representative.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

hub/internal/store/telemetry.go

@@ -446,3 +446,21 @@ func (s *Store) PruneStaleIssues(notSeenSince time.Time) (int64, error) {
 	}
 	return res.RowsAffected()
 }
+
+// DeleteAppTelemetry removes all telemetry records for a specific app.
+func (s *Store) DeleteAppTelemetry(appName string) (int64, error) {
+	res, err := s.db.Exec("DELETE FROM app_telemetry WHERE app_name = ?", appName)
+	if err != nil {
+		return 0, err
+	}
+	return res.RowsAffected()
+}
+
+// DeleteAppIssues removes all known-issue records for a specific app.
+func (s *Store) DeleteAppIssues(appName string) (int64, error) {
+	res, err := s.db.Exec("DELETE FROM app_log_issues WHERE app_name = ?", appName)
+	if err != nil {
+		return 0, err
+	}
+	return res.RowsAffected()
+}