feat(z-task-modal): implement draft handling for timeblocks and improve employee-specific timeblock management

app/src/plugins/tm@modal/task/z-task-add-time-modal.vue

@@ -86,6 +86,12 @@ export default {
 
   methods: {
     async showModal({ subtask }) {
+      // Prevent using this modal for drafts - they should be edited instead
+      if (subtask.is_draft) {
+        this.$toast.info('Pre koncepty použite režim úprav');
+        return;
+      }
+
       this.subtask = subtask;
       this.visible = true;
       this.form.hours = null;