Add scoped API keys, encrypted secrets, and audit-log UI

[jusso-dev]

Problem

Automation and monitor credentials require better secret handling and visibility into sensitive operations.

Scope

• Add scoped API keys with permissions, expiry, and last-used metadata.
• Encrypt notification credentials, monitor auth secrets, and Playwright environment secrets at rest.
• Add audit-log API filters and a minimal web UI/table for audit review.
• Add key rotation guidance and environment configuration for encryption keys.

Acceptance criteria

• API keys can be limited by scope and expiry.
• Stored secrets are encrypted and never returned in plaintext after creation.
• Audit logs can be filtered by actor, action, resource, and date range.
• Sensitive operations create audit records.
• Tests cover permission enforcement, encryption round trip, and redaction.

Notes

This issue is part of the GoUpTime product roadmap.