fix: update database property type to nullable and handle defaults in…

[ArnabChatterjee20k]

… fromArray method

[greptile-apps]

Greptile Summary

This PR makes the $database property on the Database resource nullable and guards the fromArray() factory against a missing database key by defaulting to null. The intent is correct and aligns with real-world data where the field may be absent, but two minor issues were left behind:

• The getDatabase() return type was changed to mixed rather than the more precise ?string, which unnecessarily degrades type safety for all callers.
• The @param array-shape docblock for fromArray() still declares database: string as a required, non-nullable field, making it inaccurate after this change.

Confidence Score: 4/5

• Safe to merge — the behavioural fix is correct and callers already handle nullable strings (e.g. Reader/Database::getDatabase(?string)).
• The core fix (nullable property + null default in fromArray) is sound and the existing callers of getDatabase()->getDatabase() already accept ?string. The only issues are a return type that is more permissive than needed (mixed vs ?string) and a stale docblock — neither affects runtime behaviour.
• No files require special attention beyond the two style suggestions in src/Migration/Resources/Database/Database.php.

Important Files Changed

Filename	Overview
src/Migration/Resources/Database/Database.php	Makes $database nullable and adds a null default in fromArray() — functionally correct, but getDatabase() return type was unnecessarily broadened to mixed instead of the precise ?string, and the PHPDoc shape for fromArray() was not updated to reflect the optional/nullable database key.

Comments Outside Diff (1)

1. src/Migration/Resources/Database/Database.php, line 35-43 (link)

   PHPDoc not updated to reflect nullable database key

   The @param array shape still declares database: string, but the key is now effectively optional and can be absent (defaulting to null). This makes the docblock inaccurate and may mislead callers and static analysis tools.

_{Last reviewed commit: "fix: update database..."}