feat(postgres): add native enum type support

[ErfanMomeniii]

Adds native PostgreSQL enum type support to PostgresAdapter.

Problem

PostgreSQL requires a two-step process for enum columns — first CREATE TYPE ... AS ENUM (...), then referencing that type in column definitions. Phinx only supported MySQL's inline ENUM('a','b') syntax.

See: #2258

Solution

Handle the full enum lifecycle automatically with the naming convention {table}_{column} (e.g. orders_status) to prevent cross-table collisions.

Operation	Behavior
createTable()	Emits CREATE TYPE before CREATE TABLE
addColumn()	Emits CREATE TYPE before ALTER TABLE
dropColumn()	Drops the associated enum type after column removal
dropTable()	Drops all associated enum types after table removal
getColumns()	Round-trips enums back as PHINX_TYPE_ENUM with values from pg_enum

Usage

$this->table('orders')
      ->addColumn('status', 'enum', [
          'values'  => ['pending', 'shipped', 'delivered'],
          'default' => 'pending',
      ])
      ->create();

Rollbacks work automatically — dropping a column or table cleans up the associated PostgreSQL type.

Tests

10 new integration tests covering create, add, drop column, drop table, round-trip, cross-table isolation, and schema-qualified tables.

Fixes #2258

[ErfanMomeniii]

Hi @dereuromark , could you please review it?

[dereuromark]

@MasterOdin took over maintainance.

[Copilot]

Pull request overview

Adds native PostgreSQL enum support to Phinx by introducing a managed enum-type lifecycle in PostgresAdapter (create type before table/column creation, drop type on column/table removal) and round-tripping enums back to PHINX_TYPE_ENUM via catalog inspection.

Changes:

• Add PHINX_TYPE_ENUM support to PostgresAdapter (DDL emission + column introspection for enum labels).
• Update shared type constants/comments to reflect enum support beyond MySQL.
• Add Postgres integration tests covering enum create/add/drop and round-tripping behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 6 comments.

File	Description
src/Phinx/Db/Adapter/PostgresAdapter.php	Implements enum type creation, drop cleanup, and enum detection/round-trip in getColumns().
src/Phinx/Db/Table/Column.php	Updates Column::ENUM documentation to reflect Postgres support.
src/Phinx/Db/Adapter/AdapterInterface.php	Reclassifies PHINX_TYPE_ENUM as supported by MySQL + PostgreSQL.
tests/Phinx/Db/Adapter/PostgresAdapterTest.php	Adds integration tests validating enum lifecycle and getColumns() round-tripping.

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[dereuromark]

@MasterOdin are u ok with this?

[MasterOdin]

I think there's a bug here where since using the table and column name to look up enum names, if a rename happens for either, then the link breaks on the enum. Probably should add a rename of the enum on renaming the table or column I guess? Alternative would be to do a DB look-up of the enum name when doing a drop column or drop table.