docs(api): publish generated API and event reference documentation #700

Parent epic: #679
Depends conceptually on: #695

Objective

Publish readable, versioned API and event reference documentation generated from the canonical bundled OpenAPI/AsyncAPI contracts.

Scope

• Generate static reference docs locally/offline.
• Include authentication model, tenant context, pagination, idempotency, correlation IDs, standard errors, rate/body limits, and conditional feature gates.
• Include event channel/message schemas and compatibility/deprecation policy.
• Add artifact version/commit metadata and link to raw bundled contracts.
• Validate internal links/examples and prevent secrets or production hostnames from entering examples.
• Publish as release artifact and/or static documentation site using existing repository infrastructure.

Acceptance criteria

• Generation is deterministic and requires no external SaaS.
• Every public operation/event in the bundled contracts appears.
• Examples use placeholders and safe synthetic data.
• Version selection and deprecation notices are clear.
• CI detects stale generated reference content.
• Offline/LAN operators can open the generated artifact locally.