Improve expanded task details and tag emphasis

[alteixeira20]

Summary

• label expanded task descriptions and move Edit details into the description header area
• align Add subtask and Link dependency with the GitHub links row
• keep the derived automatic status as the first task-header tag slot
• let each user feature one custom tag beside the task title by clicking tags in the expanded task
• let each user toggle the automatic status tag without mutating shared roadmap data
• hide legacy status:* tags from the custom featured-tag choices

Product decision

Featured-tag and automatic-status visibility are personal display preferences stored locally per roadmap and task. They do not create collaboration writes or alter the roadmap schema.

Validation

• focused tests added for automatic-tag filtering and the description label
• full CI requested for unit tests, lint, typecheck, build, browser tests, and API checks

Review notes

The branch intentionally keeps the underlying task/tag schema unchanged. The automatic status remains derived from task state, while the featured custom tag is a user-specific presentation choice.