feat(tasks): add task notes and descriptions

[frankie-reyes-tsg]

This pull request introduces support for rich-text (Markdown) notes on tasks, allowing users to add, edit, and view formatted descriptions for each task. It updates both the frontend and backend logic to handle the new description field, including UI enhancements for editing and previewing notes, search improvements, and data migration for legacy tasks.

Task Description/Notes Support

• Added a description field to the Task type and integrated it throughout the codebase, including migration logic to ensure existing tasks are updated with this new field. [1] [2] [3] [4]
• Updated the Redux slice (tasksSlice) and local API to support updating task descriptions, including new actions and reducers. [1] [2] [3]

UI Enhancements for Notes

• In AddTaskForm, added an expandable Markdown editor (using @uiw/react-md-editor) for adding optional notes when creating a task. [1] [2] [3] [4]
• In TaskItem, added UI to display, expand/collapse, edit, and preview notes in Markdown, with support for both truncated and full views. [1] [2] [3] [4] [5] [6]

Search Improvements

• Enhanced task search to include the new description field, allowing users to find tasks by their notes as well as their titles.

Dependency Updates

• Added the @uiw/react-md-editor package and its CSS dependencies to enable rich Markdown editing and preview.

These changes collectively provide a much richer experience for managing task notes, with robust support for Markdown formatting and seamless integration into the existing task management workflow.