💡 Feature Request: Add support for refreshing extension manifest cache (GUI + CLI)

Problem:
Joomla stores extension metadata such as the version number in the manifest_cache column of the #__extensions table during installation or update. However, if an extension is updated manually — for example via Git, FTP, or a CI deployment — the XML manifest file is updated on disk, but Joomla does not re-read this file automatically.

This leads to inconsistencies between the actual extension files and the metadata shown in the Joomla admin interface.
Most notably:

• The Extensions → Update page may incorrectly list such extensions as outdated.
• The Extensions → Manage page shows stale version and metadata information.
• Developers using Git to manage extensions must reinstall or manually update the database to reflect changes.

Currently, the only way to update the manifest_cache is to reinstall the extension or use low-level CLI/SQL workarounds.

Proposed Solution:
Add native support for refreshing the manifest_cache from the manifest XML, via both GUI and CLI:

✅ GUI (Admin Interface)

• Add a "Refresh Manifest" button or batch action in:
  • System → Manage → Extensions
  • (Optionally) inside the extension’s detail view.
• This should:
  • Re-parse the XML manifest file on disk.
  • Update the manifest_cache field with current data.
  • Show a success message (and optionally a diff — e.g. old vs new version).

✅ CLI

• Add a new command in Joomla CLI:

  php cli/joomla.php extension:refresh --name=plg_myplugin

• This should:
  • Accept either --name, or a combination of --type, --element, and --folder.
  • Perform the same logic as the GUI action to update the manifest cache.

Why it’s important:

• Ensures version and metadata consistency after manual or Git-based updates.
• Prevents false positives in the Extensions Update system.
• Reduces need for reinstalling extensions or manually editing the database.
• Improves developer experience and supports modern deployment workflows.

Security Considerations:

• Only Super Users should be able to trigger this action.
• File paths and manifest files should be strictly validated before parsing.

Optional Enhancements:

• Allow refreshing multiple extensions at once (batch mode).
• Include --all CLI option to refresh all installed extensions.