docs: document implemented AgentOps feature baselines

[Paulo Lacerda (placerda)]

Why

AgentOps already implements a broad release-readiness workflow across Evaluate, Ship, Operate, and Observe, but those capability boundaries were not captured as feature specifications. These retrospective specs establish an as-built baseline that future Spec Kit work can evolve without rediscovering existing contracts.

What

• Adds nine sequential implemented-baseline specs covering evaluation configuration/execution/results, CI/CD generation, release evidence, Doctor readiness, the read-only Cockpit, Foundry operations observability, and trace-to-regression promotion.
• Captures user scenarios, acceptance criteria, edge cases, functional requirements, measurable outcomes, assumptions, exclusions, and implementation evidence for each capability.
• Adds a completed specification-quality checklist beside every spec.
• Explicitly records current boundaries such as read-only Cockpit behavior, advisory diagnostic-category preflight, and review-required trace promotion.

Notes

Documentation only; no runtime behavior or public CLI contract changes.