feat: add project names to Slack deployment titles

[dunctk]

Changes

• Add an optional Slack setting under /notifications/slack to prefix deployment notification titles with the project name.
• Keep the current notification titles unchanged by default.
• Cover enabled, disabled, and default-off behavior with focused tests.

Issues

• Fixes Optionally include project name in Slack deployment notification titles #10926
• Supersedes feat: add project names to Slack deployment titles #10927, which was closed by the automated quality check before the PR template and local verification were completed.

Category

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

Preview

The Deployments section now includes a Show Project Name in Title checkbox. It was verified checked and persisted after a hard reload while global Slack delivery remained disabled and the webhook remained blank.

AI Assistance

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

If AI was used:

• Tools used: Codex
• How extensively: Extensively for implementation, tests, local environment and browser verification, and PR preparation.

Testing

• Started a local Coolify development instance with Docker Compose and confirmed /api/health returned OK.
• Ran php artisan test --compact tests/Feature/SlackNotificationProjectNameTest.php (2 tests, 5 assertions).
• Ran vendor/bin/pint --format agent on all changed PHP files and vendor/bin/pint --dirty --format agent.
• Verified /notifications/slack in a real browser: the option saved, remained checked after reload, and produced no browser console errors.

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.