Implements a concrete first milestone for issue #17:\n\n- Adds entity/relationship foundation schema\n- Adds extraction/linking/query/recommendation API contract\n- Adds ontology + recommendation payload contracts\n- Adds phased implementation plan\n\n@algora-pbc /claim #17

Demo video

• https://github.com/aimqwest/gyroflow/releases/download/aimqwest-pr-demos-20260512/pr34-demo-v6.mp4