6caa674c19
PostgREST translates .eq('col', null) to `col = NULL` which is always false
in SQL. The migration silently returned zero rows -> setupNewUserIdentity
fired but re-wrapped nothing -> users could set a PIN but every send threw
'Awaiting key'. Switching to .is('col', null) emits `col IS NULL` and the
migration finally finds its work.
Also makes the migration trigger idempotent and re-fires it on:
- every successful loadOrUnlockUserKey
- AuthContext startup when the user-key is already cached
so users stuck on 0.18.0 auto-recover the moment they install 0.18.1.
PinInput: focused + active-slot now show a brand-coloured ring, glow, and
a blinking caret so users see where the next keystroke lands.