[Feature] Add label/tag management tools (list, create, assign, delete)

[Herriaan]

Feature Request

The current MCP server has no tools for managing TickTick labels/tags. This makes it impossible to:

• List all existing labels/tags
• Create new labels/tags
• Assign/remove labels on tasks
• Delete unused labels/tags

Context

The TickTick API supports tags via the tags field on tasks. Adding label management would enable:

• Automated cleanup of unused tags
• Bulk label operations
• Tag-based task filtering and organization via MCP

Suggested tools

Tool	Description
list_tags	List all tags across all projects
create_tag	Create a new tag
delete_tag	Delete a tag
assign_tag	Add a tag to a task
remove_tag	Remove a tag from a task
get_tasks_by_tag	Get all tasks with a specific tag

This would complement the existing task and project management tools nicely.