Revamp workspace archive handling with async support, input validation improvements and better session management

src/db/attachments.js

@@ -33,6 +33,11 @@ export function initializeAttachments(db) {
             created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
         );
         CREATE INDEX IF NOT EXISTS upload_leases_user ON upload_leases(username);
+        CREATE TABLE IF NOT EXISTS workspace_operation_leases (
+            username TEXT PRIMARY KEY REFERENCES users(username) ON DELETE CASCADE,
+            token TEXT NOT NULL UNIQUE,
+            created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+        );
         CREATE TRIGGER IF NOT EXISTS release_message_attachment AFTER DELETE ON message_attachments
         BEGIN
             DELETE FROM attachments WHERE id = OLD.attachment_id AND status = 'attached'