Header/nav config 403 (signed in but not entitled to this app) left the
shell spinning forever. Attach HTTP status to thrown errors (ApiError),
stop retrying a 403, and render a clear access-denied panel with a
sign-in-as-different-account action.
APP_ID/ORG_ID -> 519/900000103 (all other uuids already match dev).
Runtime-config BASE_URL (config.js + SAME_ORIGIN, dev fallback), relative
vite base + BASE_HREF placeholder for the frontgen artifact contract.
API updates from krishna_sales: rdbms lookup via workflow_uuid + form_data,
values[] multi-filters, preset_alias, wf-lookup/dataset-options/me endpoints,
numeric org_id on login.
