Add app version display to DevPanel

[kevinmaes]

Overview

Display the app version from package.json in the DevPanel (accessed via Cmd-D).

Requirements

• Read version from package.json semver field (currently 0.3.0)
• Display in DevPanel UI
• Version should update automatically when package.json version changes

Suggested Implementation

• Import version at build time (Vite's import.meta.env or import package.json)
• Add version display above or below the existing "Test sound" button
• Format: "Version: 0.3.0" or similar

Files to Modify

• src/DevPanel/DevPanel.tsx - Add version display
• May need to configure Vite to expose package.json version

Acceptance Criteria

• Version from package.json is visible in DevPanel
• Version updates when package.json version changes
• No hardcoded version strings