Use GORM AutoMigrate instead of raw SQL to create the
database_versions table, since PostgreSQL does not support the
datetime type used in the raw SQL (it requires timestamp).
Add a version check that runs before database migrations to ensure
users do not skip minor versions or downgrade. This protects database
migrations and allows future cleanup of old migration code.
Rules enforced:
- Same minor version: always allowed (patch changes either way)
- Single minor upgrade (e.g. 0.27 -> 0.28): allowed
- Multi-minor upgrade (e.g. 0.25 -> 0.28): blocked with guidance
- Any minor downgrade: blocked
- Major version change: blocked
- Dev builds: warn but allow, preserve stored version
The version is stored in a purpose-built database_versions table
after migrations succeed. The table is created with raw SQL before
gormigrate runs to avoid circular dependencies.
Updates #3058
