toolkit: add /spec and /build-loop rows to the CLAUDE.md phase-command ownership table

[genwave-radio]

📚 Problem

CLAUDE.md § Phase commands lists /explore, /design, /plan, /document with the file each owns, but omits /spec (owns spec files via bdd-specs) and /build-loop (owns the PLAN.md checkbox state and task commits). Codex A06 asked for one owner per artifact; the table already does that, it is just incomplete.

✅ Fix

Add two rows:

Command	Owns	Purpose
/spec	tests/**/Story*Specs.cs (pending specs)	BDD specs from stories
/build-loop	docs/PLAN.md checkboxes, task commits	Build each task through review

📎 Source

docs/AI_TOOLKIT_AUDIT_CLAUDE.md §5 A06.