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/trimming.md

@@ -0,0 +1,51 @@
+---
+name: trimming
+description: Trimming patterns for Remotion - cut the beginning or end of animations
+metadata:
+  tags: sequence, trim, clip, cut, offset
+---
+
+Use `<Sequence>` with a negative `from` value to trim the start of an animation.
+
+## Trim the Beginning
+
+A negative `from` value shifts time backwards, making the animation start partway through:
+
+```tsx
+import { Sequence, useVideoConfig } from "remotion";
+
+const fps = useVideoConfig();
+
+<Sequence from={-0.5 * fps}>
+  <MyAnimation />
+</Sequence>;
+```
+
+The animation appears 15 frames into its progress - the first 15 frames are trimmed off.
+Inside `<MyAnimation>`, `useCurrentFrame()` starts at 15 instead of 0.
+
+## Trim the End
+
+Use `durationInFrames` to unmount content after a specified duration:
+
+```tsx
+<Sequence durationInFrames={1.5 * fps}>
+  <MyAnimation />
+</Sequence>
+```
+
+The animation plays for 45 frames, then the component unmounts.
+
+## Trim and Delay
+
+Nest sequences to both trim the beginning and delay when it appears:
+
+```tsx
+<Sequence from={30}>
+  <Sequence from={-15}>
+    <MyAnimation />
+  </Sequence>
+</Sequence>
+```
+
+The inner sequence trims 15 frames from the start, and the outer sequence delays the result by 30 frames.