Performance: Add create-and-publish and update-and-publish endpoints

[AndyButland]

Description

With Umbraco 14+ we've split the save and publish operation into two. As a performance improvement, we might consider new API endpoints that perform create/update and publish in one operation, similar to how we do in Umbraco 13 - which may give us some options for optimization.

I've done that in a fairly simple way in this PR. Testing comparing the API calls of separate save and publish versus combined doesn't suggest much value - around 3% in a rough test - but there may be more we could do here. For now the only optimizations I've found are in:

• Not having to retrieve the content item we have just saved in the save operation in order to publish it.
• Avoiding a second validation after save when we know we have already validated the content.

It feels like any further benefit would require a larger change at the service level - and mean we'd have to blur the nice split we currently have between the IContentEditingService and IContentPublishingService. If we did that for example we could look at putting the whole operation in a single lock and scope.

If we move forward with this, there's still a task needed to actually use the new API endpoints from the backoffice.

Change Summary

• Adds new Management API endpoints for combined create/update and publish operations:
  • POST /document/create-and-publish - Creates a document and immediately publishes it
  • PUT /document/{id}/update-and-publish - Updates a document and immediately publishes it
• Adds new PublishAsync(IContent, ...) overload to IContentPublishingService that accepts an already-loaded content entity, avoiding an extra database round-trip
• Adds skipValidation parameter to skip redundant validation when the caller has already validated the content
• Extracts BuildCultureAndScheduleModel helper method to DRY up schedule model creation

Review and Testing

• Verify create-and-publish endpoint creates and publishes a document in a single request
• Verify update-and-publish endpoint updates and publishes a document in a single request
• Consider further optimizations we should make and whether there's value in the work so far in this PR.

[Copilot]

Pull request overview

This PR adds new Management API endpoints to combine create/update and publish operations into single requests, improving efficiency and developer experience. The changes introduce create-and-publish and update-and-publish endpoints that perform both operations atomically, along with a new PublishAsync overload that accepts an already-loaded content entity to avoid redundant database lookups.

Key Changes

• New combined operation endpoints that perform create/update and immediate publish in one request
• Service layer optimization with an IContent overload that skips redundant database queries
• Extracted BuildCultureAndScheduleModel helper method to reduce code duplication in the service layer

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
CreateAndPublishDocumentController.cs	New controller providing POST endpoint to create and immediately publish documents in a single request
UpdateAndPublishDocumentController.cs	New controller providing PUT endpoint to update and immediately publish documents in a single request
CreateAndPublishDocumentRequestModel.cs	Request model extending CreateDocumentRequestModel with cultures property for immediate publishing
UpdateAndPublishDocumentRequestModel.cs	Request model extending UpdateDocumentRequestModel with cultures property for immediate publishing
IContentPublishingService.cs	Added new PublishAsync overload accepting IContent entity with skipValidation parameter to avoid database round-trips
ContentPublishingService.cs	Implemented new PublishAsync overload and extracted BuildCultureAndScheduleModel helper method for code reuse
ContentPublishingServiceTests.Publish.cs	Added comprehensive tests for the new PublishAsync overload with skipValidation parameter
PublishDocumentRequestModel.cs	Removed extra blank line (formatting cleanup)
PublishDocumentController.cs	Removed unused import statement (code cleanup)