StemJSON v1.0.0

Initial public release of the StemJSON specification.

• Full specification: spec/v1.0.md
• LLM-optimised edition: spec/v1.0-ai.md
• License: OWFa 1.0 with attribution requirement (§1.5)
• Trademark policy: TRADEMARK_POLICY.md

Subsequent revisions will be recorded in CHANGELOG.md.