Initial commit: InTono — app KMP per l'apprendimento musicale

App Kotlin Multiplatform (Android/iOS/Desktop) con Compose Multiplatform:
controllo intonazione (YIN), pratica guidata, metronomo, ear training,
sfide, scansione spartiti via AI, spartiti bundled e pentagramma con
glifi tipografici, travature, battute e spaziatura proporzionale.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

video/.agents/skills/remotion-best-practices/rules/animations.md

@@ -0,0 +1,27 @@
+---
+name: animations
+description: Fundamental animation skills for Remotion
+metadata:
+  tags: animations, transitions, frames, useCurrentFrame
+---
+
+All animations MUST be driven by the `useCurrentFrame()` hook.  
+Write animations in seconds and multiply them by the `fps` value from `useVideoConfig()`.
+
+```tsx
+import { useCurrentFrame } from "remotion";
+
+export const FadeIn = () => {
+  const frame = useCurrentFrame();
+  const { fps } = useVideoConfig();
+
+  const opacity = interpolate(frame, [0, 2 * fps], [0, 1], {
+    extrapolateRight: "clamp",
+  });
+
+  return <div style={{ opacity }}>Hello World!</div>;
+};
+```
+
+CSS transitions or animations are FORBIDDEN - they will not render correctly.  
+Tailwind animation class names are FORBIDDEN - they will not render correctly.