feat(audit): implement cursor-based pagination for audit logs

[martinvibes]

• Add AuditPage struct with items, next_cursor, and count fields for stable pagination
• Replace get_audit_log return type from Vec to AuditPage with cursor support
• Integrate remitwise-common dependency for clamp_limit utility function
• Use saturating arithmetic to prevent overflow panics in cursor calculations
• Add comprehensive pagination tests covering empty logs, single/multi-page scenarios, and cursor boundary conditions
• Enable deterministic replay of audit logs by consumers through stable cursor-based pagination

closes #254

[martinvibes]

@Baskarayelu pls review :)