Orion documentation

• spec/orion-spec.md — the product specification (v1, June 2026): positioning, principles, query and schema models, adapter contracts, lifecycle, tenancy, receipts, CLI, MCP, capability matrix, determinism boundary, verification regime.
• spec/revision.md — the framework-agnostic re-cut (v2 delta, October 2026): repository shape, package map, ports, the same-connection invariant, the Univeros module, core layout, work packages. Where it disagrees with v1, it wins.
• decisions.md — the append-only decisions log.

Per-package documentation lives in each packages/<name>/README.md; the agent skill is .ai/skills/orion/SKILL.md.