v0.22.1 — real Chimera brand icon in the desktop app

Changed

• Real Chimera brand icon in the desktop app. Replaced the placeholder 🔺 emoji mark (rail, sidebar header, chat empty-state, assistant avatar) with the actual icon (blue lion + cyan serpent on deep navy), via a shared BrandMark component, and pointed the favicon + PWA manifest at it too.

Install: pip install -U "chimera-agent[desktop]" then chimera app.