Without a household row the signIn callback has nothing to attach the
first user to, causing "No household membership" on first load. Add
scripts/seed.mjs (plain ESM, only needs postgres which is already in the
image) and run it from the entrypoint after migrations. Idempotent — skips
if a household already exists. Default calendars/lists are created by the
signIn callback when the first user authenticates.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
