Add ALGORITHM/LOCK support to Index operations

[jamisonbryant]

Summary

Extends the ALGORITHM and LOCK clause support added in #955 (for Column operations) to also cover Index operations. This allows addIndex to pass algorithm and lock options through the fluent API on MySQL.

Usage:

$table->addIndex('email', [
    'algorithm' => MysqlAdapter::ALGORITHM_INPLACE,
    'lock' => MysqlAdapter::LOCK_NONE,
])->update();

Changes:

• Add algorithm and lock properties, getters/setters, and valid options to Index class
• Wire algorithm/lock from Index through getAddIndexInstructions() in MysqlAdapter
• Handle FULLTEXT indexes which use post-steps (algorithm/lock clause inlined into the SQL)
• Add 9 tests mirroring the Column algorithm/lock test coverage

Note: Drop index operations are out of scope, matching Column behavior where getDropColumnInstructions also does not support algorithm/lock (the method signature only receives string parameters, not the object).

Test plan

• PHPStan passes (composer stan)
• New Index algorithm/lock tests pass against MySQL 8.4
• Existing Column algorithm/lock tests still pass (no regression)
• CI passes on all PHP versions

[Copilot]

Pull request overview

Extends MySQL ALTER TABLE ... ALGORITHM=... / LOCK=... support from column operations to index operations by adding algorithm/lock options to the Index value object and wiring them through MysqlAdapter alter-instruction generation (including FULLTEXT special-casing).

Changes:

• Add algorithm and lock properties + getters/setters + option mapping to src/Db/Table/Index.php.
• Pass index algorithm/lock options through MysqlAdapter::getAddIndexInstructions() (including FULLTEXT post-step handling).
• Add MySQL adapter integration tests for index algorithm/lock behaviors.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

File	Description
tests/TestCase/Db/Adapter/MysqlAdapterTest.php	Adds new MySQL integration tests for index algorithm/lock options and batched behavior.
src/Db/Table/Index.php	Introduces algorithm/lock as supported index options via new properties and setters/getters.
src/Db/Adapter/MysqlAdapter.php	Wires algorithm/lock from Index into AlterInstructions and FULLTEXT SQL generation.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.