feat: make webhooks and documents editable instead of delete-and-recreate

Both could only be created and deleted. For a webhook that is actively harmful:
recreating it issues a new signing secret, so the receiver that verifies the
X-ApiCore-Signature header against the old one starts rejecting every delivery
without anyone changing it on purpose.

Backend:
- New PATCH /webhooks/:id behind a new webhooks:update permission, covering the
  target URL, the event selection and the active flag - the last of which had
  no way to be set after creation at all, so a misbehaving receiver could only
  be deleted. The signing secret is deliberately left alone and stays out of
  the audit log.
- A changed webhook URL runs through the same assertPublicWebhookUrl SSRF check
  as a new one; without that the edit would have been a way around the guard
  create() applies. Covered by a test.
- New PATCH /documents/:id behind a new documents:update permission, for
  re-linking a document filed against the wrong record and correcting its
  display name. Re-linking validates the new target with the existing
  assertEntityExists; the stored file is untouched.

Frontend:
- New webhook edit dialog. The event labels and the toggle helper moved out of
  the create dialog into lib/webhooks/labels.ts so both use one copy.
- Documents can be renamed from the attachment card.

Re-linking a document to a different record has no UI yet: it needs a two-step
picker (colony, then inspection) that is not worth building unprompted.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

ApiCore-Backend/src/auth/permissions/permission-catalog.ts

@@ -223,6 +223,7 @@ export const PERMISSION_CATALOG = [
     [
       ['read', 'Ansehen'],
       ['upload', 'Hochladen'],
+      ['update', 'Bearbeiten'],
       ['delete', 'Löschen'],
     ],
     1800,
@@ -233,6 +234,7 @@ export const PERMISSION_CATALOG = [
     [
       ['read', 'Ansehen'],
       ['create', 'Anlegen'],
+      ['update', 'Bearbeiten'],
       ['delete', 'Löschen'],
     ],
     1900,