v0.4.0 — Studio, The Board & OSS foundations

Highlights:

• 🛠️ Studio — configure & test in one place (Roster / Avatars / Actions), with a visual agent↔avatar↔voice↔seat binding that saves to agents.local.json.
• 📋 The Board — agents can show a floating, draggable Markdown panel (tables, lists, reports) while speaking a short summary.
• ⚙️ Writable config API + ElevenLabs voice picker; redesigned "Your office" hub with a guided empty state.
• 🌱 Open-source foundations: CHANGELOG, MAINTAINERS, ROADMAP, SUPPORT, CODEOWNERS, issue forms, .editorconfig.

See the full CHANGELOG.