Add metrics to Identity

[JamesNK]

Fixes #52996

[JamesNK]

Ready to review. Please take a look.

[JamesNK]

@MackinnonBuck I've added metrics to some of the passkey methods you recently added.

[Copilot]

Pull Request Overview

This PR instruments UserManager and SignInManager with OpenTelemetry-compatible metrics, extends test helpers to support metrics collection, and updates existing tests and project references to validate the new metrics.

• Introduces UserManagerMetrics and SignInManagerMetrics and registers them via DI
• Augments MockHelpers and TestUserManager/TestSignInManager to accept an IMeterFactory and emit metrics
• Updates tests across Identity.Test to assert that the correct tags are recorded for each metric

Reviewed Changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/Identity/Extensions.Core/src/UserManagerMetrics.cs	New metrics class for user manager operations
src/Identity/Extensions.Core/src/UserManager.cs	Instruments all public methods to record metrics and exposes ServiceProvider
src/Identity/Core/src/SignInManagerMetrics.cs	New metrics class for sign-in manager operations
src/Identity/Core/src/SignInManager.cs	Instruments sign-in methods to record metrics
src/Identity/test/Shared/MockHelpers.cs	MockUserManager/TestUserManager updated to accept IMeterFactory
src/Identity/test/Shared/MetricsHelpers.cs	New helper for asserting metric tag collections
src/Identity/test/Identity.Test/UserManagerTest.cs	Tests updated to collect and assert on emitted metrics
src/Http/Authentication.Core/src/AuthenticationService.cs	Minor doc-comment fix in authentication service
src/Http/Authentication.Abstractions/src/IAuthenticationService.cs	Minor doc-comment fix in auth service interface

Comments suppressed due to low confidence (3)

src/Identity/Extensions.Core/src/UserManager.cs:1255

• Method name 'ResolveFromtRolesCoreAsync' contains a typo and is inconsistent with the public API. Rename it to 'RemoveFromRolesCoreAsync' to match 'RemoveFromRolesAsync'.

            throw;

src/Http/Authentication.Core/src/AuthenticationService.cs:148

• [nitpick] The doc comment has a redundant 'in'; consider revising to 'Sign in a principal for the specified authentication scheme.'

    /// Sign in a principal in for the specified authentication scheme.

src/Http/Authentication.Abstractions/src/IAuthenticationService.cs:43

• [nitpick] The doc comment has a redundant 'in'; consider revising to 'Sign in a principal for the specified authentication scheme.'

    /// Sign in a principal in for the specified authentication scheme.

[MackinnonBuck]

Are we considering RoleManager out of scope for these metrics?

[JamesNK]

API review feedback applied.

Please do a final review and lets get this merged 🙏

[JamesNK]

/azp run

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