## What
Fixes two bugs found while writing component tests for the platform
webhooks page (follow-up to FE-3749):
1. The webhooks API nests error details under an `error` key (`{ error:
{ code, message } }`), but the shared `handleError` only reads a
top-level `message`. This meant the friendly rate-limit message ("wait a
minute and try again") never actually fired, it always fell back to a
generic error. Fixed with a local unwrapping `handleError` in
`platform-webhooks-fetchers.ts`.
2. Every mutation handler on the page (`mutateAsync` for
create/update/delete/regenerate-secret/send-test-event/retry) left the
re-thrown error from React Query uncaught, producing an unhandled
promise rejection on every failure, even though the error toast itself
was already correct. Fixed by wrapping each call in try/catch.
## Why
Found while writing the stacked test PR for FE-3749; filed as
[FE-4620](https://linear.app/supabase/issue/FE-4620/two-webhook-error-handling-bugs-found-while-writing-retryrate-limit)
since it's a correctness fix independent of the test work.
## Testing
Manually verified both fixes on localhost: rate-limit retry now shows
the friendly message, and no `Uncaught (in promise)` errors appear in
the console on any mutation failure.
## What
Wires the existing (mocked) Platform Webhooks UI to the real Management
API backend, per FE-3749.
- New `data/platform-webhooks/` query/mutation hooks, calling the real
`/v2/organizations/{slug}/webhooks/...` and
`/v2/projects/{ref}/webhooks/...` endpoints
- Updated `PlatformWebhooks.types.ts` to match the real API contract
(field names, shapes)
- Added a signing secret field to the create-endpoint form (API requires
a user-provided secret, not server-generated like the mock assumed)
- Removed the event-type column from the deliveries table (the real
list-deliveries endpoint doesn't return event type, only the
single-delivery endpoint does)
- Removed `PlatformWebhooks.mock.ts` / `.store.ts` and their tests
## Why
UI was built ~80% against mock data months ago; this closes the gap to a
real, working feature.
## Known open items (not blocking, tracked separately)
- `name` field has no backend storage yet — client-only for now, open
question with Ali/Paweł
- Deliveries table only fetches the backend's default single page — real
server-side pagination not yet wired (see FE-3750)
## Follow-up PR (stacked)
Tests for the new `data/platform-webhooks/` hooks (MSW-based), per the
ticket's own scope split.
## Testing
Manually tested end-to-end against local backend: created/edited/deleted
an endpoint, verified the real signature using webhook.site,
independently recomputed the HMAC and confirmed it matches the
`webhook-signature` header.
Linear: FE-3749
---------
Co-authored-by: Charis Lam <26616127+charislam@users.noreply.github.com>
Monica Khoury