**Refactor directory scanning and add scan task support**

- Added a new `scan_directory` task to enable folder scans as asynchronous tasks while maintaining compatibility with the immediate backend.
- Introduced the `reconcile` function, replacing `generate_directory` for improved separation of concerns between database writes and read operations.
- Established a unique constraint on `Directory` (`one_directory_name_per_parent`) to prevent duplicate directories under the same parent.
- Added a "Scan" button to the frontend for re-reading folders from disk, along with new task invocation endpoints in the API.
- Updated tests across modules to validate the new `scan_directory` task, unique constraints, and database indexing logic.
- Improved cleanup logic for stale files, directories, and thumbnails to handle concurrent operations efficiently.
- Simplified `scan_comics` management command by removing user dependency and aligning it with the new `reconcile` function.
- Enhanced frontend components (`TheComicReader`, `TheComicList`, and others) to include lifecycle method cleanups, prevent memory leaks, and handle task-based scans.

frontend/src/views/ReadView.vue

@@ -15,25 +15,20 @@ export default {
   },
   data () {
     return {
-      comic_data: {},
       comic_loaded: false,
     }
   },
   methods: {
-    updateType() {
-      let comic_data_url = '/api/read/' + this.selector + '/type/'
-      api.get(comic_data_url)
-          .then(response => {
+    checkComicExists() {
+      api.get('/api/read/' + this.selector + '/type/')
+          .then(() => {
               this.comic_loaded = true
           })
           .catch((error) => {console.log(error)})
       }
   },
   mounted () {
-    this.updateType()
-  },
-  beforeUpdate() {
-    this.updateType()
+    this.checkComicExists()
   }
 }
 </script>