Support Public File Sharing via Link and Password Protection

Stalwart’s file storage and sharing system has massive potential, but it is currently limited to internal organization members. To enhance collaboration, I would like to propose expanding the file sharing capabilities to external users:

Public Link Sharing: Allow users to generate a public, read-only link for files or folders that anyone can access without needing a Stalwart account.

Password Protection: Add an optional feature to set a password for the generated public link to ensure security.

Use Case / Benefit:
This will allow users to easily share files or large documents with external clients/partners via email, breaking the barrier of internal-only file sharing.