docs: Add CLAUDE.md documentation for key .NET projects

[hifi-phil]

Description

Some Claude memory files that have been generated against a template to attempt to standardise memory file product for Umbraco

Add comprehensive CLAUDE.md files for major Umbraco projects:

• Root CLAUDE.md: Multi-project repository overview
• Umbraco.Core: Interface contracts and domain models
• Umbraco.Infrastructure: Implementation layer (NPoco, migrations, services)
• Umbraco.Cms.Api.Common: Shared API infrastructure
• Umbraco.Cms.Api.Management: Management API (1,317 files, 54 domains)
• Umbraco.Web.UI.Client: Frontend with split docs structure

Each file includes:

• Architecture and design patterns
• Project-specific workflows
• Edge cases and gotchas
• Commands and setup
• Technical debt tracking

[AndyButland]

Seems pretty good to me @hifi-phil. I've given just a cursory review to check it's on the right track and added a few comments where I saw errors.

[AndyButland]

Not (just) headless.

[AndyButland]

This isn't correct/complete - see https://dev.azure.com/umbraco/D-Team%20Tracker/_wiki/wikis/D-Team-Tracker.wiki/2435/Branch-Naming

[AndyButland]

See https://dev.azure.com/umbraco/D-Team%20Tracker/_wiki/wikis/D-Team-Tracker.wiki/2585/Pull-Request-Naming

[hifi-phil]

does this exist in the repo somewhere?

[AndyButland]

Wouldn't say this is legacy, at least yet.

[AndyButland]

Not correct (yet).

[AndyButland]

More to say on this now - see #20820

[AndyButland]

MySQL/PostgreSQL via community packages - not (yet) true.

[AndyButland]

Should be NPoco not EF Core, but not really relevant in this project anyway.

[iOvergaard]

Added a few suggestions around the Client. In general, some of the agentic actions are over-simplified, but I'm not sure if the agent can figure it out by looking at the existing code anyway.

In the future, we might have use of more flows, such as:

• Adding a dashboard
• Adding a workspace
• Using the existing Content workspace

[iOvergaard]

Perhaps it would help to add the URL to the raw schema, which we (manually) copy over to the OpenAPI.json file: /umbraco/swagger/management/swagger.json

[iOvergaard]

Some resources are already on V1.1. Well, 1 operation is. See ValidateUpdateDocumentController#ValidateV1_1.

[iOvergaard]

I see Umbraco.Web.UI was mentioned several times. The Umbraco.Web.UI project only controls these values in development mode. In a real Umbraco project, all settings are generated through the appsettings.template.json files through the UmbracoTemplate dotnet template.

[iOvergaard]

The interfaces described below only apply to new extensions, and not necessarily all new features.

[iOvergaard]

Suggested change

	export class UmbMyElement extends UmbElementMixin(LitElement) {
	export class UmbMyElement extends UmbLitElement {

[iOvergaard]

Suggested change

	async #handleClick() {
	const { data, error } = await this.#context?.load();
	if (error) {
	this._error = error;
	return;
	}
	this._data = data;
	}
	render() {
	return html`
	<button @click=${this.#handleClick}>Load</button>
	${this._data ? html`<p>${this._data.name}</p>` : ''}
	`;
	}
	@state()
	private _data?: UmbMyModel;
	async #handleClick() {
	const { data, error } = await this.#context?.load();
	if (error) {
	this._error = error;
	return;
	}
	this._data = data;
	}
	render() {
	return html`
	<uui-button @click=${this.#handleClick} label="Load"></uui-button>
	${this._data ? html`<p>${this._data.name}</p>` : nothing}
	`;
	}

[iOvergaard]

Suggested change

	<button @click=${this.#handleClick}>Load</button>
	<uui-button @click=${this.#handleClick} label="Load"></uui-button>

[iOvergaard]

Suggested change

	**Step 9: Add localization**
	```typescript
	// 10. Add to src/Umbraco.Web.UI.Client/src/assets/lang/en.ts and other appropriate files
	{
	actions: {
	load: 'Load'
	}
	}
	// 11. Use the localize helper (`this.localize.term()`) in the element
	render() {
	return html`
	<uui-button @click=${this.#handleClick} label=${this.localize.term('actions_load')></uui-button>
	${this._data ? html`<p>${this._data.name}</p>` : ''}
	`;
	}
	async #handleClick() {
	try {
	this._loading = true;
	const { data, error } = await this.#context?.load();
	if (error) {
	this._error = this.localize.term('errors_receivedErrorFromServer');
	return;
	}
	this._data = data;
	} catch (error) {
	this._error = this.localize.term('errors_defaultError');
	console.error('Load failed:', error);
	} finally {
	this._loading = false;
	}
	}
	// 12. Outside elements (such as controllers), use the Localization Controller
	export class UmbMyController extends UmbControllerBase {
	#localize = new UmbLocalizationController(this);
	#notificationContext?: typeof UMB_NOTIFICATION_CONTEXT.TYPE;
	constructor(host: UmbControllerHost) {
	super(host);
	this.consumeContext(UMB_NOTIFICATION_CONTEXT, (notificationContext) => {
	this.#notificationContext = notificationContext;
	});
	}
	fetchData() {
	// Show error
	this.#notificationContext?.peek('positive', {
	data: {
	headline: this.#localize.term('speechBubbles_onlineHeadline'),
	message: this.#localize.term('speechBubbles_onlineMessage'),
	},
	});
	}
	}

[hifi-phil]

In the future, we might have use of more flows, such as:

• Adding a dashboard
• Adding a workspace
• Using the existing Content workspace

I have a plan to provide this type of knowledge using Claude Code Skills. This will allow us to supply much more specific knowledge including examples, guides, etc in a context efficient way.

[Migaroez]

I will make the proposed changes myself now that I have access to your fork.
Other things todo:

• check patch strategy with Kenn
• Cleanup double info in project files that are already the root file

[Migaroez]

Suggested change

	- Registered via Composers
	- Handlers registered by extention method `AddNotificationHandler`

[Migaroez]

Suggested change

	- Must call `scope.Complete()` to commit
	- Must call `scope.Complete()` to commit or set the parameter autocomplete to true when calling `ICoreScopeProvider.CreateCoreScope()`, this will complete the scope upon disposal

[Migaroez]

Suggested change

- **Patching**: JsonPatch.Net for PATCH operations

Not used as far as I know and can see, and agreed in discussions that this should be avoided at all cost (might be used be an in house) package? @AndyButland @kjac

[Migaroez]

Suggested change

	- Enables fine-grained authorization and operation-specific logic
	- Enables fine-grained authorization and operation-specific logic
	- **Responsibilities**: entrypoint/routing, authorization and mapping
	- **avoid**: business logic directly in controllers (there are a few known violations)

[Migaroez]

Suggested change

	**Why JsonPatch.Net?**
	- RFC 6902 compliant JSON Patch support
	- Used for partial updates (PATCH operations)
	- See `ViewModels/JsonPatch/JsonPatchViewModel.cs`

[Migaroez]

Suggested change

	**Authorization**:
	```csharp
	// Example from CreateDocumentController.cs:22
	private readonly IAuthorizationService _authorizationService;
	// Authorization checked in base controller methods, not attributes
	protected async Task<IActionResult> HandleRequest(request, Func<Task<IActionResult>> handler)
	{
	var authResult = await _authorizationService.AuthorizeAsync(User, request, policy);
	// ...
	}
	```
	**Authorization**:
	- Basic authorization is done trough policies and the `AuthorizeAttribute`
	```csharp
	// Example from DocumentTreeControllerBase.cs, the user needs at least access to a section that uses trees
	[Authorize(Policy = AuthorizationPolicies.SectionAccessForContentTree)]

• Authorization that needs (parts of) the payload are done manually trough the IAuthorizationService

// Example from CreateDocumentController.cs:22
private readonly IAuthorizationService _authorizationService;

// Authorization checked in base controller methods, not attributes
protected async Task<IActionResult> HandleRequest(request, Func<Task<IActionResult>> handler)
{
    var authResult = await _authorizationService.AuthorizeAsync(User, request, policy);
    // ...
}

[Migaroez]

Suggested change

	- Services are registered in Composers via DI
	- Services are registered via DI in builder extensions

[Migaroez]

Suggested change

	// 3. Register in composer
	// 3. Add to builder extensions

[Migaroez]

Suggested change

	Composers register services and configure the application:
	Composers register services and configure the application, this is to make the system easily extendible by package developers and implementors or internally for temporary service registration for use in short lived code, for example migrations :