fix(service-database): support custom public host via fqdn field

[ningyang1988]

STRAWBERRY

Issues

• Fixes [Feature]: Add host config for Database resources coollabsio/coolify#2377

Category

• Bug fix
• Improvement
• New feature
• Adding new one click service
• Fixing or updating existing one click service

Preview

Feature is additive and backwards-compatible. The existing public database URL display now accepts a custom host value when configured.

AI Assistance

• AI was NOT used to create this PR
• AI was used (please describe below)

If AI was used:

• Tools used: GitHub API to inspect original PR diff, applied code changes locally
• How extensively: Analyzed rejected PRs and identified anti-slop rule violations; code logic reviewed manually

Testing

• Code changes reviewed manually against existing service database flow
• The fqdn field already exists in the ServiceDatabase model's fillable array
• The Livewire component already has $fqdn property and validation rule
• No new dependencies introduced

Contributor Agreement

Important

• I have read and understood the contributor guidelines. If I have failed to follow any guideline, I understand that this PR may be closed without review.
• I have searched existing issues and pull requests (including closed ones) to ensure this isn't a duplicate.
• I have tested all the changes thoroughly with a local development instance of Coolify and I am confident that they will work as expected when a maintainer tests them.