feat(services): service instance create/edit/view modal and delete modal

[Hannahbird]

PR Checklist

• Linting Test is passing
• Code is well documented
• If applicable, a PR in the epinio/docs repository has been opened

Summary

Fixes #

EPINIO-508 & EPINIO-511

Implements service instance create, edit, and view flows via a shared modal component using Trailhand UI components.

Occurred changes and/or fixed issues

• Add ServiceInstanceModal component with create, edit, and view modes
• View mode opens on row name click with read-only fields and Edit Configuration button to switch inline to edit
• Modal title shows instance name and state in edit/view modes
• Dismissible false prevents backdrop close; dirty check on Cancel prompts discard confirmation inline with no nested modal
• Replace native select placeholders with trailhand-dropdown
• Create flow: closes modal immediately after API call, binds apps and re-fetches in background; re-asserts svc.metadata post-create to prevent followLink response merge from breaking bind URL
• Edit flow: closes modal before bind/unbind so response-parsing errors do not surface as save errors
• Fix unbind endpoint in services model: /unmounted 404 to /unbind
• Catalog service detail table: add Edit/Delete action menu per row
• Catalog Create action navigates to services list with query params to open modal prefilled with the selected catalog service

Technical notes summary

Areas or cases that should be tested

• Create a service instance without app bindings and confirm it appears in the table within a few seconds
• Create a service instance with one or more apps selected and confirm the bound apps appear after the background bind completes
• Open a second create modal immediately after creating an instance and confirm the form is blank with no discard confirmation
• Edit a service instance and change the bound apps, confirm changes persist after save
• Unbind an app from a service instance and confirm it is removed
• Open a service instance by clicking its name, confirm all fields are disabled, then click Edit Configuration and make a change
• Discard flow: open create or edit, make changes, click Cancel, confirm the discard prompt appears, click Keep Editing and confirm the modal stays open with data intact
• Create from a catalog service detail page and confirm the catalog service field is prefilled
• Verify the Edit and Delete actions appear in the action menu on both the services list and catalog service detail table

Areas which could experience regressions

Screenshot/Video

[dcharles525]

LGTM