v0.9.0

Changelog

• f46182f chore(v0.9.0): bump version, document scenario IPC bus, add release notes
• f0b9ce8 docs(claude): add Identity anchor paragraph to Project Overview
• 8b8201f docs(identity): lock tagline as contract layer, add 'Who is testplay for?' section
• 3a0b631 docs(measurement): add v0.9 shadow warm-cache threshold note
• b936232 docs(measurement): record v0.9 shadow benchmark — Opus user, 34% ratio
• 7375b07 docs(roadmap): split v1.0 into v0.9 Network Primitives + v1.0 NGO Harness
• 7dd2ec1 feat(ipc): add polling reader for IPC bus (v0.9 phase 2)
• b0982a4 feat(ipc): add scenario-scoped IPC bus writer (v0.9 phase 1)
• cd07cdf feat(scenario): integrate IPC events into per-instance events.ndjson (v0.9 phase 6)
• 05ed464 feat(scenario): retain IPC bus dirs under same policy + .gitignore patch (v0.9 phase 7)
• 518fa85 feat(scenario): wire IPC bus into scenario orchestration (v0.9 phase 4+5)
• f8faab6 refactor(runid): move Generate from runsvc to internal/runid (v0.9 phase 3)