feat(ai): add the storage for an OpenAI-compatible gateway provider

Three dedicated User columns — base URL, optional bearer, model — for a
provider whose endpoint the user chooses. They are separate from the
OpenAI columns on purpose: the OpenAI arm pins api.openai.com, so it must
share no column with a user-supplied host, and a gateway must never
receive the key issued for OpenAI.

The bearer joins the encrypted-column registry and the rotation script;
the three columns join the account-wipe reset set.

src/lib/data-wipe/wipe-plan.ts

@@ -262,6 +262,9 @@ export const USER_RESET = {
   aiAnthropicKeyEncrypted: null,
   aiLocalKeyEncrypted: null,
   aiOpenaiKeyEncrypted: null,
+  aiCompatBaseUrl: null,
+  aiCompatKeyEncrypted: null,
+  aiCompatModel: null,
   aiProviderChain: Prisma.DbNull,
   aiResponseTimeoutSeconds: null,
   disableCoach: false,