Post-merge cleanups after #403 (customer portal):
- Renumber 090_backfill_photo_dimensions_v2.js → 096 to follow #403's
090_add_customer_accounts ... 095_add_customer_portal_flag chain.
- customerAccountsService.js: TODO note on must_change_password
documenting that the column is decorative until an admin
pre-loaded-password flow ships (mirrors what adminAuth does for
must_change_password today).
- customerAuth.js: doc-comment on the /login route explaining why the
customerPortal feature flag deliberately doesn't gate it (toggle off
hides UI, doesn't revoke existing-customer access; deactivate
individual accounts to lock out).
- 095_add_customer_portal_flag.js: header comment said "Migration 094"
(copy-paste from 094) — now matches the filename.