chore: update package versions and improve code readability

- Bump 'tmp' package version from 0.2.5 to 0.2.6 in package.json
- Change version from 3.0.0-pre-alpha.0.1 to 3.0.0-beta-1.0.0 in package-lock.json
- Update various dependencies in package-lock.json:
  - 'brace-expansion' from 5.0.5 to 5.0.6
  - 'dompurify' from 3.3.3 to 3.4.8
  - 'js-cookie' from 3.0.5 to 3.0.8
  - 'lodash' from 4.17.23 to 4.18.1
- Refactor date range selection in CalendarView.vue for better readability

frontend/package.json

@@ -47,6 +47,6 @@
   },
   "overrides": {
     "minimatch": "10.2.4",
-    "tmp": "0.2.5"
+    "tmp": "0.2.6"
   }
 }

frontend/src/views/personal/CalendarView.vue

@@ -628,8 +628,8 @@ export default {
             this.dragStartDate = null;
         },
         selectDateRange(startStr, endStr) {
-            const start = new Date(startStr);
-            const end = new Date(endStr);
+            let start = new Date(startStr);
+            let end = new Date(endStr);
             
             if (start > end) {
                 [start, end] = [end, start];