X_TEST_ISLAND_STATES_UNKNOWN
Means
no island state manifest answers to that name
Typical cause
findIslandStates(all, name) resolved nothing. A typo and an island whose states were never declared are one symptom and two different edits, so cause lists every valid name
Fix
name one of the islands the cause lists — or, when none is listed, declare one beside the island: export const states = defineIslandStates({ island: 'apps/web/app/settings/settings.island.tsx', states: [] })