The post editor lost the Pinterest board picker during a UI rewrite,
causing scheduled posts to fail in production with 'Pinterest board_id
is required'. This restores the picker and locks the contract with
validation + tests so the regression cannot happen silently again.
Backend:
- PostController: pinterestBoards is now Record<account_id, Board[]>
(mirrors the TikTok creator-info pattern); supports multi-account.
- UpdatePostRequest: 'platforms.*.meta.board_id' rule + after-validator
rejects Publishing/Scheduling Pinterest posts without board_id.
Frontend:
- PinterestSettings.vue: Combobox board picker with empty-state warning;
emits update:meta with board_id.
- ScheduleTab / PostEditorSidebar / Edit pass pinterestBoards down by
social_account_id.
Tests (6 new):
- UpdatePostRequestTest: rejects publishing/scheduling without board_id
across pin/carousel/video pin; allows draft without board_id;
pinterest error doesn't block sibling platforms in multi-platform.
- PinterestPublisherTest: publisher throws for carousel + video pin
when no board_id (existing image-pin case kept).
1542 tests passing.