Reuse the existing SafeWebhookUrl rule on the S3 Storage endpoint field so
the create and edit forms go through the same URL-normalization path as
webhook settings. Adds a matching guard inside S3Storage::testConnection()
so background callers (scheduled backups, database import reuse) also
validate the endpoint before building the S3 client.
Also fixes an IPv6-bracket edge case in SafeWebhookUrl so `http://[::1]`
style hosts are normalized before the filter_var IP check — the rule's
own loopback test was already asserting this behaviour.
- Introduced `ValidationPatterns` class to standardize validation rules and messages for various fields across multiple components.
- Updated components including `General`, `StackForm`, `Create`, and `Show` to utilize the new validation patterns, ensuring consistent validation logic.
- Enhanced error messages for required fields and added regex validation for names and descriptions to improve user feedback.
- Adjusted styling in the `create.blade.php` view for better visual hierarchy.
