## Summary
- **Backend**: Add JSON validation for the `blocknote` subfield in rich
text API inputs — rejects values that aren't valid JSON or aren't arrays
(BlockNote content is always `PartialBlock[]`). This prevents corrupted
data from being persisted to the database.
- **Frontend**: Replace all 5 unprotected `JSON.parse` calls on
blocknote content with the safe `parseJson` utility from
`twenty-shared`. Invalid content now degrades gracefully (empty block /
empty string / unchanged passthrough) instead of crashing the app.
- **Tests**: Added integration tests for invalid blocknote JSON (both
GraphQL and REST), unit tests for the new validation, and updated
existing test constants to use valid BlockNote JSON.
## Context
A user reported a `SyntaxError: Expected ',' or ']' after array element`
crash caused by malformed blocknote JSON stored in the database. The
data had `"children":[]` nested inside the `content` array instead of as
a sibling property. The API accepted this invalid JSON because it only
validated that `blocknote` was a string, not that it contained valid
JSON. On the frontend, 5 call sites used bare `JSON.parse` with no error
handling, causing a white-screen crash.
## Test plan
- [x] Unit tests pass: `validate-rich-text-field-or-throw.util.spec.ts`
(10/10)
- [x] Integration tests pass: `rich-text-field-create-input-validation`
(8/8)
- [ ] Verify creating a note with valid rich text still works end-to-end
- [ ] Verify API returns clear error when blocknote contains invalid
JSON
- [ ] Verify frontend renders empty block instead of crashing when
encountering corrupted data
🤖 Generated with [Claude Code](https://claude.com/claude-code)
