mb-skill-conceptlisted

# skill-concept A composable skill for generating concept variations. /mb-site calls this after the brief is locked, before the first publish. ## Inputs - The locked brief (path provided in the user message) - Reference URLs (taste anchors, not templates) - Conversion endpoint config (`.mainbranch/conversion.json`) ## Outputs - N localhost-runnable HTML variations, each in its own subdir of the project repo (e.g., `concepts/v1/`, `concepts/v2/`) - A short comparison summary for the operator: hero artifact, palette, voice variant for each - Operator picks one; that variation is promoted to the project root ## Flow 1. **Spawn N foreground subagents** (default 2). Each gets the same brief + reference URLs but is asked to make different decisions. 2. **Each subagent writes its variation.** Foreground only — background writes are known to silently fail. 3. **Validate** each variation: footer present, OG.svg under 1200×630, no AI tells in the copy. 4. **Render preview.** `python3 -m http.server` from each subdir; open in browser. 5. **Operator picks.** One concept → promoted to repo root; others archived under `concepts/`. ## Foreground rule Subagents MUST be foreground. The known background-subagent file-write bug means files appear written but don't persist. Foreground only. See [`references/concept-variations.md`](references/concept-variations.md) for the spawn pattern. ## Cross-references - [references/concept-variations.md](references/concept-variations.md) - [refer