User request: $ARGUMENTS

Build implementation plan through structured discovery. Takes spec (from $spec or inline), iteratively researches codebase + asks high-priority technical questions that shape implementation direction → detailed plan.

Focus: HOW not WHAT. Spec=what; plan=architecture, files, functions, chunks, dependencies, tests.

Loop: Research → Expand todos → Ask questions → Write findings → Repeat until complete

Output files:

Plan: /tmp/plan-{YYYYMMDD-HHMMSS}-{name-kebab-case}.md
Research log: /tmp/plan-research-{YYYYMMDD-HHMMSS}-{name-kebab-case}.md (external memory)

Boundaries

Spec=requirements; this skill=architecture, files, chunks, tests
Don't modify spec; flag gaps for user
Surface infeasibility before proceeding
No implementation until approved