feat: Implement proper schema migration structure (Issue #94)

[subhanLabs]

Closes #94

Implements a proper versioned schema migration structure for the CODECHECK plugin, replacing the previous ad-hoc approach where table creation was split across three disconnected methods called manually from setEnabled().

Approach

This implementation follows the pattern used by the PKP PLN plugin (pkp/pln), which is the only official PKP plugin with a full install + upgrade migration structure. The pattern is compatible with OJS 3.5, confirmed via pkp-lib/stable-3_5_0/classes/plugins/Plugin.php.

Changes

New structure

classes/migration/
├── install/
│   └── CodecheckSchemaMigration.php   ← all 4 tables, fresh install only
└── upgrade/
    └── I94_AddMissingColumns.php      ← defensive column-level changes

How it works

Fresh install: setEnabled() calls getInstallMigration()->up() which creates all 4 tables (codecheck_metadata, codecheck_orcid_tokens, codecheck_issue_labels, codecheck_status) and then runs all upgrade migrations. Since columns already exist in the freshly created table, the upgrade migrations do nothing extra.

Existing install (upgrade): Schema::hasTable() is true so table creation is skipped, existing data is untouched. Upgrade migrations then run and use Schema::hasColumn() guards to add only the columns that are missing from older installs.

OJS Plugin Gallery install: getInstallMigration() hooks into OJS's own Installer::postInstall event automatically via the parent Plugin class, no manual intervention needed.

Adding future columns: Create a new
classes/migration/upgrade/I{issue}_Description.php with a hasColumn guard, then add one line calling it at the bottom of the install migration.
Both fresh installs and existing installs converge to the same schema state.

Key fixes compared to before

	Before	After
Fresh install	3 methods called manually in setEnabled()	Single entry point via getInstallMigration()
Existing install with new columns	Silently skipped, column never added	I94_AddMissingColumns adds missing columns safely
OJS gallery install	Bypassed entirely	Hooks into Installer::postInstall automatically
down()	Dropped tables — risked data loss	Throws DowngradeNotSupportedException
Reset button	Called down() from migration	Explicit drops in resetSchema(), separate from migration system

Other changes

• Remove classes/migration/CodecheckSchemaMigration.php (old file)
• Remove unused CodecheckSchemaMigration import from Manage.php
• Remove private $migration property from CodecheckPlugin
• Bump version.xml from 0.0.0.0 to 1.0.0.0

References

• PLN plugin migration pattern: https://github.com/pkp/pln/tree/main/classes/migration
• Plugin::getInstallMigration(): https://github.com/pkp/pkp-lib/blob/stable-3_5_0/classes/plugins/Plugin.php#L236

[nuest]

Thanks for the first iteration. Can you please update the documentation as well?

What I find especially important: Where is the order of the upgrade scripts configured?

If I understand correctly, that would be in the up() function.

Also make clear in the documentation that "adding a column" is only one thing that could happen, an upgrade script may also process all records (e.g., rename an allowed value), insert content, e.g., for settings, or remove fields/columns/tables that are not used anymore.
Correct?

[subhanLabs]

Thanks for the first iteration. Can you please update the documentation as well?

What I find especially important: Where is the order of the upgrade scripts configured?

If I understand correctly, that would be in the up() function.

Also make clear in the documentation that "adding a column" is only one thing that could happen, an upgrade script may also process all records (e.g., rename an allowed value), insert content, e.g., for settings, or remove fields/columns/tables that are not used anymore. Correct?

Added a docblock to the install migration explaining that the order of calls at the bottom of runUp() defines execution order, and that upgrade scripts aren't limited to adding columns, they can rename, migrate data, insert defaults, or remove things too.