Parent: #138
Goal
Make Storybook the canonical review surface for PostKit Admin Email Builder (EmailBuilder.js via EmailTemplateAdmin), with block/layout/template/state/interaction coverage.
Implements the comprehensive Storybook coverage request on branch feat/139-email-builder-mui-canvas (PR #142).
Acceptance
- Every built-in block exposed by PostKit has meaningful stories
- Realistic full emails (welcome, OTP, reset, transactional, receipt, report)
- Editor/admin states (empty, loading, save success/failure, etc.)
- Deterministic play interactions where practical
- build-storybook passes; no live backend
Parent: #138
Goal
Make Storybook the canonical review surface for PostKit Admin Email Builder (EmailBuilder.js via EmailTemplateAdmin), with block/layout/template/state/interaction coverage.
Implements the comprehensive Storybook coverage request on branch feat/139-email-builder-mui-canvas (PR #142).
Acceptance