Add mutation for creating users

[Knerio]

close #693

[Copilot]

Pull request overview

This PR adds a GraphQL mutation for admin users to create new user accounts in the system. The implementation includes service layer logic with proper authorization, validation, and audit logging.

• Implements usersCreate mutation with password confirmation validation
• Adds service layer with admin-only authorization and comprehensive error handling
• Introduces audit event logging for user creation actions

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
app/graphql/mutations/users/create.rb	Defines the GraphQL mutation with input validation and password repeat check
app/services/users/create_service.rb	Service layer implementation with authorization, user creation, and audit logging
app/graphql/types/mutation_type.rb	Registers the new mutation in the GraphQL schema
app/policies/global_policy.rb	Adds create_user permission for admin users
app/models/audit_event.rb	Adds user_created action type to audit event enum
spec/graphql/mutation/users/create_spec.rb	GraphQL mutation tests covering admin/non-admin scenarios and validation
spec/services/users/create_service_spec.rb	Service layer tests covering authentication and validation scenarios
docs/graphql/mutation/userscreate.md	API documentation for the new mutation

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[github-actions]

GitLab Pipeline Action

General information

Link to pipeline: https://gitlab.com/code0-tech/development/sagittarius/-/pipelines/2173862387

Status: Passed
Duration: 3 minutes

Job summaries

rspec: [ee]

Coverage report available at https://code0-tech.gitlab.io/-/development/sagittarius/-/jobs/12183960616/artifacts/tmp/coverage/index.html
Test summary available at https://gitlab.com/code0-tech/development/sagittarius/-/pipelines/2173862387/test_report
Finished in 19.79 seconds (files took 11.76 seconds to load)
1232 examples, 0 failures
Line Coverage: 91.42% (4154 / 4544)
[TEST PROF INFO] Time spent in factories: 00:10.975 (40.42% of total time)

rspec: [ce]

Coverage report available at https://code0-tech.gitlab.io/-/development/sagittarius/-/jobs/12183960615/artifacts/tmp/coverage/index.html
Test summary available at https://gitlab.com/code0-tech/development/sagittarius/-/pipelines/2173862387/test_report
Finished in 19.82 seconds (files took 11.11 seconds to load)
1185 examples, 0 failures
Line Coverage: 90.82% (3986 / 4389)
[TEST PROF INFO] Time spent in factories: 00:10.705 (40.32% of total time)

rubocop

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