# B4 — Wizard step deduplication

## Problem

Greenfield wizard testing showed completed wizard steps could be executed again after the menu marked them `[done]`. In practice this made the Providers/API-key flow and Skills flow appear twice in one wizard run.

There was a second related API-key duplication path: when the Providers step was completed with no key, `gatewayConfigStage` still prompted for `ANTHROPIC_API_KEY` during Finish because it only skipped the gateway API-key prompt when `providerKey` was non-empty.

## Diagnosis

- `runMenuLoop` labeled completed sections with `[done]`, but still dispatched the selected step again if the user selected that row.
- Quick Start ran Providers and Skills but did not mark those sections complete in `completedSections`.
- `runFinishPath`/`quickStartPath` defaulted `providerType` to `none` for gateway config, which made it impossible for `gatewayConfigStage` to distinguish:
  - provider step completed and user intentionally skipped the key, vs.
  - provider step was never run.

## Fix

- Added a shared menu section key helper and a completed-step guard in `runMenuLoop`.
- Completed menu steps now log a skip message instead of re-running their stage.
- Quick Start marks Providers and Skills complete after running them.
- Finish/Quick Start now pass `state.providerType` as-is to gateway config instead of defaulting to `none`.
- `gatewayConfigStage` treats `providerType: 'none'` as an explicit completed provider setup with no key and skips the second gateway API-key prompt.

## Verification

- Added unified wizard regression coverage asserting repeated Providers/Skills menu selections only execute each stage once.
- Added gateway config coverage asserting `providerType: 'none'` does not prompt for a gateway API key and writes no API key env var.
- Targeted: `pnpm --filter @mosaicstack/mosaic test -- unified-wizard gateway-config`
- `pnpm format:check`
- `pnpm typecheck`
- `pnpm lint`
- `pnpm build`
- `pnpm test`
- Codex code review: approve.
- Codex security review: no findings.