fix(whatsapp): stop reconnect failing when the token lists several WABAs

[viethung0o0]

Summary

• WhatsApp Reconnect (Ads Optimization → Automatic Events) failed at random with "Reconnect returned a different WhatsApp Business Account" for businesses that own several WABAs, even when the user re-authorised the same account every time.
• Root cause: the WABA was read from debug_token as granular_scopes[whatsapp_business_management].target_ids[0]. A system-user token lists every WABA the business has shared with the app, and Meta does not keep that order stable between tokens, so the first entry only matched by luck.
• Fix: read the full list of granted WABAs and match the expected WABA by membership. Connect keeps the same behaviour for a fresh signup (first grant), but now validates a client-selected wabaId against the whole list instead of the first entry.

Changes

• integrations/whatsapp/src/api/auth.ts: getSharedWabaId → getSharedWabaIds, returning every granted WABA id (the single-id helper had no remaining callers).
• New apps/builder/src/features/integration-whatsapp/libs/waba-grant.ts: resolveGrantedWabaId / requireGrantedWabaId with a WABA_GRANT_FAILURES map, shared by connect and reconnect so the selection rule lives in one place.
• actions/reconnect.action.ts: accepts the reconnect when the existing WABA is anywhere in the grant list; still rejects when the token does not cover it.
• actions/connect.action.ts: deriveSignupTargets takes the requested wabaId and uses the same helper; the separate first-entry mismatch check is removed.
• Tests: whatsapp-waba-grant.test.ts (new), multi-WABA cases in whatsapp-reconnect-action.test.ts, whatsapp-connect-action-registration.test.ts, and integrations/whatsapp/__tests__/auth.test.ts.

Test plan

• pnpm lint
• pnpm --filter builder check-types && test (402 files / 2704 tests)
• pnpm --filter @chatbotx.io/integration-whatsapp check-types && test (24 files / 217 tests)
• Manual: on a business with several WABAs, press Reconnect on the WhatsApp Ads Optimization tab several times in a row — no more random "different WhatsApp Business Account" error; reconnecting with a different WABA selected still fails with that error.
• Manual: fresh WhatsApp connect (single-WABA and multi-WABA business) still reaches phone-number selection.