v0.5.0 — Versioning and Compatibility Rules

Exploratory draft. Defines spec_version grammar, editorial/additive/breaking change classification (decision D-005), the consumer compatibility matrix, deprecation policy, and extension-point stability for AIOS artifacts.

Status: Tests v0.1 concepts, v0.2 relationships, v0.3 semantic conventions, and v0.4 schemas; cannot freeze before them. Several v0.5-specific acceptance-criteria gates also remain open (see specification/v0.5/acceptance-criteria.md). Not a stable release; do not claim AIOS conformance from this artifact.

Asset: zipped markdown docs for the v0.5 milestone (README, versioning, examples, acceptance-criteria).