hidden subtree is now built as "predictable" to avoid duplicating it in sync

db/migrations/0212__delete_all_attributes_of_named_notes.js

@@ -0,0 +1,21 @@
+module.exports = () => {
+    const cls = require("../../src/services/cls");
+    const beccaLoader = require("../../src/becca/becca_loader");
+    const becca = require("../../src/becca/becca");
+
+    cls.init(() => {
+        beccaLoader.load();
+
+        const hidden = becca.getNote("_hidden");
+
+        for (const noteId of hidden.getSubtreeNoteIds({includeHidden: true})) {
+            if (noteId.startsWith("_")) { // is "named" note
+                const note = becca.getNote(noteId);
+
+                for (const attr of note.getOwnedAttributes()) {
+                    attr.markAsDeleted("0212__delete_all_attributes_of_named_notes");
+                }
+            }
+        }
+    });
+};