clarification-phase

<quick_start> Resolve ambiguities in spec.md using AskUserQuestion tool:

1. Extract [NEEDS CLARIFICATION] markers from spec.md
2. Prioritize using matrix (Critical/High → ask, Medium/Low → assumptions)
3. Call AskUserQuestion with ≤3 questions (batched, multiSelect for subsystems)
4. Receive user answers synchronously
5. Integrate into spec.md, remove all markers
6. Add Clarifications (Resolved) section with deferred assumptions

Inputs: spec.md with [NEEDS CLARIFICATION] markers Outputs: Updated spec.md (no markers), clarifications.md (record) </quick_start>