fix: allow contacts-only mining when no folders are selected

The Start Mining button was disabled when no email folders were
selected, even when Google Contacts sync was enabled. Now the button
stays enabled and startMiningBoxes() proceeds when googleContactsSyncEnabled
is true, allowing contacts-only mining without folder selection.

Author: baderdean

frontend/src/components/mining/stepper-panels/mine/MinePanel.vue

@@ -47,8 +47,10 @@
       v-if="!$leadminerStore.activeMiningTask"
       id="mine-stepper-start-button"
       :disabled="
+        (sourceType === 'email' && $leadminerStore.isLoadingBoxes) ||
         (sourceType === 'email' &&
-          ($leadminerStore.isLoadingBoxes || totalEmails === 0)) ||
+          totalEmails === 0 &&
+          !$leadminerStore.googleContactsSyncEnabled) ||
         $leadminerStore.isLoadingStartMining
       "
       :loading="$leadminerStore.isLoadingStartMining"
@@ -397,11 +399,12 @@ function openMiningSettings() {
 }
 
 async function startMiningBoxes() {
-  if (
+  const hasCheckedBoxes =
     Object.keys(selectedBoxes.value).filter(
       (key) => selectedBoxes.value[key].checked && key !== '',
-    ).length === 0
-  ) {
+    ).length > 0;
+
+  if (!hasCheckedBoxes && !$leadminerStore.googleContactsSyncEnabled) {
     openMiningSettings();
     $toast.add({
       severity: 'error',