[Design] Unify the three Logo visual systems + redo the icon

[dushaobindoudou]

Problem (verified by founder during dogfooding)

Three different logos = users perceive "three products":

• Tray/Dock electron/icon-renderer.ts:1-40 (green, yellow-ish at small size)
• Main console src/components/shared/AnimatedLogo.tsx:1-142 (bright green face)
• Floating orb src/components/FloatingIcon/FloatingIcon.tsx:310-342 (Siri orb green/purple)

See docs/UI_DESIGN_AUDIT.md -> B1.

Decision

• One logo concept (keep "two eyes + V mouth" O-V-O wordmark from icon-renderer)
• Recolor to systemBlue #007aff
• Redo the yellow icon - low legibility at small size, looks cheap, it's the first impression

Acceptance

• Single source-of-truth logo geometry rendered to all sizes
• All logo surfaces use systemBlue #007aff
• State changes via state-color system, NOT logo switching
• Regenerate build/icon*.png + .icns (use scripts/generate-icons.ts)
• shared/OvoLogo.tsx = single import for in-app logo
• Before/after screenshots (tray/dock/console/orb)