Add Support for Starring or Highlighting Tasks

Problem Statement

It's difficult to quickly access or highlight important tasks I want to revisit later. There's no way to prioritize visually without using a label or workaround.

Proposed Solution

• Add a "star" or "highlight" or "pin" option to mark important tasks.

• Create a "Starred" / "Pinned" filter or section at the side-bar for easy access.

• Add folders support to organize Starred Tasks.

Relevant Context

Example: https://i.imgur.com/lnzRWS8.png, https://i.imgur.com/DsrwfFK.png.

Does this feature align with Kaneo's focus on simplicity?

Yes, because it's a low-friction way to improve task prioritization without altering the core structure.

Originally requested by @Rodaviva29 on 2025-07-28. Original GitHub request #414.