rzv CLI 0.3.4: workspace and API-key management

rzv CLI 0.3.4 adds workspace, API-key, and prepaid-purchase commands; the matching service update is pending.

• rzv workspaceAdds workspace settings, member, and invitation commands, including invitation create, resend, revoke, and accept.
• rzv api-keys <list|create|rename|revoke>Adds lifecycle management for delegated read API keys. A created secret is shown once. Rename changes only an active key's display name.
• rzv billing purchasesLists a bounded set of prepaid purchases for the selected workspace.
• rzv billing portal <order-reference>Requests a sensitive Creem-hosted billing-management link only for an eligible verified payer. The command does not download invoices or manage saved payment methods.
• rzv CLI 0.3.4 is available from the installer. The matching service update is pending. These commands will work once that update is deployed. @runzivo/customer-sdk 0.3.4 is not published to a package registry. Live provider behavior and invoice delivery have not been verified. Payment-provider activation and invitation email delivery remain disabled.