Chunk Validation

[exyw]

Summary
Adds validation for profile chunks before save: when the user clicks Save (or Save All Changes in the pending-changes modal), all chunks are validated for safety and sensitivity (PII). If any chunk fails, save is blocked and a toast shows the validation error(s).

Changes

1. Chunk validation scope
   Validate/chunks now checks only safe (no harmful/illegal/NSFW content) and sensitive (no personal PII such as personal phone, email, exact address).
   Removed: name validation (belongsToUser, detectedNames), category validation (categoryValid, categoryMatchesContent), relevance, and the suggestion field.
   Request body no longer requires fullName; only text is used.
2. Shared validation logic
   lib/resume/validateChunk.ts
   validateChunkText(text, openai) returns { safe, sensitive, reason }.
   Single place for the validation prompt and schema; used by both the API route and the save flow.
3. Validate/chunks API
   app/api/validate/chunks/route.ts
   Uses validateChunkText from the shared lib (no duplicated prompt/schema).
   Response shape: { safe, sensitive, reason }.
   Keeps existing auth, rate limiting, and body checks.
4. Validation on save
   app/profile/chunks/actions.ts (Server Action)
   validateChunksAction(chunks: { id, text }[]) validates all non-empty chunks (in parallel).
   Returns { success: true } or { success: false, errors: { chunkId, reason }[] }.
   Requires an authenticated user.
   components/profile/chunks/hooks/useChunkData.ts
   In saveChunks(), after determining there are changes, calls validateChunksAction with current chunks.
   If validation fails: throws an Error with a short message (one chunk: that reason; multiple: e.g. "3 chunks didn't pass validation. <first reason>").
   If validation passes: existing delete/upsert/vector-store logic runs unchanged.
5. User-facing errors
   components/profile/ActionsButton.tsx
   Save button: catch uses toast.error(err.message) so validation (and other) errors show in a toast.
   Pending-changes modal Save All Changes: same error handling so validation failures from the modal also show a toast.

Behaviour
Save → validate all current chunks → if any fail → one toast with summary (and first reason if multiple) → no DB write.
Save → validate all pass → chunks and categories are saved as before → success toast.

How to test
Edit profile, add or edit a chunk with clearly sensitive content (e.g. personal phone or email) or unsafe content.
Click Save (or Save All Changes in the modal).
Expect a toast with the validation message and no save.
Fix or remove the offending content and save again; expect a successful save and success toast.