feat(enterprise): add audit-log query commands

[xe-nvdk]

Context

arcli logs reads recent in-memory application logs from /api/v1/logs. It does not read Arc Enterprise audit records from /api/v1/audit/*, and the similar terminology can hide that coverage gap.

Scope

Add a distinct arcli audit command tree covering:

• logs with event type, actor, database, since, until, limit, and offset filters
• stats with an optional since value

Map to GET /api/v1/audit/logs and GET /api/v1/audit/stats.

Acceptance criteria

• Help clearly distinguishes audit records from arcli logs application output
• RFC3339 timestamps and numeric pagination inputs are validated client-side
• Audit logs support table, JSON, and CSV; stats support table and JSON
• Server pagination fields are preserved in JSON output
• Enterprise-license and admin-permission failures are reported clearly
• Typed client and command tests cover filters, empty results, and error paths
• README/help and release notes document the commands