Applies per-version upgrade steps for PhoenixFlags.
Not invoked directly — mix igniter.upgrade phoenix_flags composes this
task automatically, passing <from> <to> versions. For each version bump
between from and to, the matching upgrader runs (e.g. generating a new
migration).
Upgrade steps
0.5.0— generates a migration that callsPhoenixFlags.Migration.up(version: 2), adding thesystem_flags_audittable used by the audit log and enabling the:secretflag type.0.6.0— generates a migration that callsPhoenixFlags.Migration.up(version: 3), widening the value columns fromvarchar(255)totext(encrypted secrets easily exceed 255 characters) and moving the schema version into the newsystem_flags_metatable.0.9.0— generates a migration that callsPhoenixFlags.Migration.up(version: 4), adding thesystem_flag_targetsandsystem_flag_target_conditionstables used by targeting rules.