Add auto-managed magerun2 wrapper

[Aquive]

Closes #85

Summary

• Installs ~/.magebox/bin/magerun2 wrapper during bootstrap — no manual version management required
• Detects Magento version from composer.lock and maps to the correct n98-magerun2 version: 7.5.0 for Magento < 2.4.5, latest GitHub release for 2.4.5+
• GitHub API is called at most once — on first use when no phar is installed. All subsequent invocations are fully offline
• SHA256 checksum verification on download (gracefully skipped if not available)
• Integrates with magebox check to show wrapper and phar status
• Documentation updated: php-wrapper.md, bootstrap.md, commands.md

How it works

magerun2 cache:flush
  → ~/.magebox/bin/magerun2 (shell wrapper)
    → magebox magerun-resolve [--project-dir=...]
      → detects Magento version from composer.lock
      → returns path to correct phar (downloads once if needed)
    → ~/.magebox/bin/php <phar> cache:flush

Version selection

Magento version	n98-magerun2
2.4.0 – 2.4.4	7.5.0 (legacy series)
2.4.5 and up	Latest release from GitHub

Tested

Confirmed working for:

• Magento 2.4.3
• Magento 2.4.6
• Magento 2.4.7

[jakwinkler]

Does it ruin as magerun ?
I'm all forward for it, maybe we can add mrun as an alias? ;-)
PR looks good, but I don't have time to test this one locally, @peterjaap up for grabs :-)

[Aquive]

@jakwinkler it runs with magerun2. Any alias is possible. Should this be included or should one do it in their own aliases?

I tested it it works great on my end :) Looking forward to have this in the next release.

[jakwinkler]

It is fine, but I don't work with a lot of projects lately so I leave it to you and @peterjaap to merge this ;-)