Make me an app where you can spray paint digitally using the main device (a laptop or a computer) and a phone. The way how this will work is that the phone will automatically pair to the main device via room code. After the device is paired, they can choose a color from the endless color library and hold their camera up to the main devices screen. Then all they will need to do is press the spray paint button on the phone screen, and it will show the paint on the specific area the camera is at. The closer to the camera is to the screen, the thinner the paint will be (like actual spray paint) There will also be an option to clear the paint on the main device.

Additional context from clarifying questions:
Q1: What should happen when a user sprays paint in your app—should the paint effect be permanent on the canvas until cleared, fade away over time, or layer transparently so previous strokes remain visible underneath?
A1: Permanent until the user clears the entire canvas
Q2: Beyond color selection and spray painting, what other tools or features should be available in your app?
A2: Spray paint plus brush size/pressure controls and undo for individual strokes
Q3: Who is the primary user of this spray paint app—what's the main use case you're building for?
A3: Individual artists experimenting with digital spray paint technique on their own
Q4: How should the camera positioning affect the spray effect—should the distance control both spray thickness AND coverage area, or only the thickness?
A4: Only thickness changes—closer = thinner, farther = thicker paint

IMPORTANT BUILD INSTRUCTIONS:

• Focus on CORE features only. Do not add extra polish, advanced features, or nice-to-haves.
• Do NOT overthink the design or architecture. Keep it simple and functional.
• Write all files in parallel where possible. Minimize thinking time.
• Skip animations, transitions, and complex interactions unless explicitly requested.
• Use simple, clean components. No over-engineering.
• Target completion in under 3 minutes. Speed over perfection.
• Ship a working MVP, not a feature-complete product.
• Do NOT install or suggest any integrations (Supabase, Blob, databases, etc). Use mock data and localStorage only.
• Do NOT prompt for user approval or wait for manual steps. Build everything autonomously.
• CRITICAL: The app MUST have a working root page at "app/page.tsx" (or "pages/index.tsx") that renders the main UI immediately. Never generate an app where "/" is empty or shows a file picker — the root route must show the primary feature of the app. If you create multiple sub-pages, "app/page.tsx" should still render the main dashboard/home view, not a redirect or empty component.