1.5.0: GraphQL API — AuditLogEntryType and query/subscription support

[eclectic-coding]

A mountable GraphQL endpoint for querying the audit trail from API-first apps.

• AuditLogEntryType — GraphQL object type exposing all public fields
• Query.auditLogEntries(event:, itemType:, itemId:, actorId:, since:, until:, page:) — filterable, paginated
• Query.auditLogEntry(id:) — single entry with full diff
• Subscription.auditLogEntryCreated(itemType:, itemId:) — real-time stream (requires Action Cable)
• Mounts at /audit/graphql; authentication re-uses RailsAuditLog.authenticate
• Shipped as optional gem rails_audit_log-graphql to avoid forcing graphql-ruby on all users