## Summary
- The `AddStandalonePageFastInstanceCommand` migration was failing with:
`default for column "type" cannot be cast automatically to type
core."navigationMenuItem_type_enum"`
- The migration was missing `DROP DEFAULT` / `SET DEFAULT` around the
`ALTER COLUMN TYPE` for `navigationMenuItem.type`. PostgreSQL cannot
automatically cast the existing default (`'VIEW'::old_enum`) to the new
enum type.
- The same 3-step pattern (DROP DEFAULT → ALTER TYPE → SET DEFAULT) was
already correctly applied for `pageLayout.type` in the same migration —
this fix brings `navigationMenuItem.type` in line.
