Groom and add backlog task

Interactively groom new tasks and add to development backlog

Creating a formal backlog item with vertical slice definition when you have a new feature or bug to track

• · Optional task description argument
• · User responses to: task name, user story, acceptance criteria, slice, dependencies, priority

• · Task file created at docs/dev/backlog/XXX-task-name.md
• · INDEX.md updated with new task in backlog table
• · Confirmation summary with task number and path

• · Read (docs/dev/INDEX.md, existing backlog files)
• · Write (new task file, updated INDEX.md)
• · Bash (ls for next task number)

• · docs/dev/ directory exists
• · docs/dev/INDEX.md file exists with Quick Stats and Backlog table
• · docs/dev/backlog/ or docs/dev/done/ directories exist

• · docs/dev/ structure missing
• · User cancels during grooming
• · Task number conflict (same file created twice)

• · Derives priority based on blockers and scope (P2/P3/P4 rubric)
• · Detects slice from file names that will be modified
• · Auto-generates next task number from filesystem scan
• · Validates acceptance criteria completeness (3-6 items)