Merged, with one adjustment.
Confirmed the bug end to end: `PricingTab.tsx:369` types the payload as `{ error?: string }` and feeds it to `new Error(errorPayload.error || ...)`, so the `{ message, details }` object landed in the toast as `[object Object]` — exactly what #12494 reported.
The one change I made before merging: `validation.error.message` is the fixed constant `"Invalid request"` (see `validateBody` in `src/shared/validation/helpers.ts:44`), so it would have swapped an unreadable toast for an uninformative one. The repo already has `formatValidationMessage()`, added in #10849 for precisely this case — it returns `"field: reason"` naming the first offending field. Merged with that instead, so a bad pricing value now says which field it was.
Validated on `release/v3.8.51`: `typecheck:core` clean, `check-file-size` OK. Rebased onto the release branch — the PR was cut from `main`, which is ~3695 commits behind the active branch.
Thank you for the report and the fix.
82f78b3b3b