Elements: Cleanup element TODOs in infrastructure

[kjac]

Description

This is the infrastructure equivalent of #22399

No new added functionality to test here; visual inspection only.

[claude]

PR Review

Target: origin/v18/dev - Based on commit: e1f88ce86e5fd77f7daaaa192ca914687bf77955

Resolves several TODO ELEMENTS markers: extracts CultureAndScheduleRequestModel / ScheduleRequestModel to ViewModels.Content, centralises publish-schedule validation into PublishableContentPresentationFactoryBase, and consolidates duplicated entity-builder code in ContentBaseFactory into a shared generic BuildPublishableEntity helper.

• Modified public API: IElementPresentationFactory (new method); CultureAndScheduleRequestModel and ScheduleRequestModel namespace changed from ViewModels.Document to ViewModels.Content
• Affected implementations (outside this PR): All external implementations of IElementPresentationFactory; external consumers referencing the old ViewModels.Document namespace for these two types
• Other changes: Element entity dates (CreateDate, UpdateDate, PublishDate) now call .EnsureUtc() via the shared builder -- aligning element behaviour with documents (bug fix; no impact for UTC-stored dates)

Note

Complexity advisory -- This PR may benefit from splitting.

Layer spread: API Management (11 files) + Infrastructure (4 files) + Tests (1 file) = 3 layers, 16 files. The changes are tightly coupled so splitting may not be practical.

This is an observation, not a blocker. The full review follows below.

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Important

• src/Umbraco.Cms.Api.Management/Factories/IElementPresentationFactory.cs:52: CreateCulturePublishScheduleModels is added to a public interface without a default implementation. Any external implementation of IElementPresentationFactory will fail to compile. Per CLAUDE.md Pattern 3, a default implementation should be provided -- IDocumentPresentationFactory already sets this precedent with its equivalent method using StaticServiceProvider. See inline comment for a suggested default.

• src/Umbraco.Cms.Api.Management/ViewModels/Document/PublishDocumentRequestModel.cs: CultureAndScheduleRequestModel and ScheduleRequestModel were public types in ViewModels.Document; removing them is a binary breaking change for consumers who import them from that namespace. If any v18 beta NuGet packages shipped these types there, keep [Obsolete] subclasses in the original namespace pointing to the new location. If v18 has had no public releases with these types, this can be dismissed.

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Suggestions

• src/Umbraco.Cms.Api.Management/Factories/PublishableContentPresentationFactoryBase.cs:131: New protected method CreateCulturePublishScheduleModels is missing an XML doc comment while all other members in the class have one.

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Request Changes

The IElementPresentationFactory missing default is a concrete breaking-change violation per the project convention. Please address that and confirm (or address) the namespace move. Happy to take another look after!

[kjac]

The Claude review correctly points out breaking changes, and I have labelled the PR accordingly.

The breaking changes are OK here, though. We can make compile time breaking changes for a new major version, and I'd rather make the changes obvious now than try to hide them behind a default implementations and left-over shims.

[AndyButland]

Again all looks good. I just found a few things to fix/consider.