Prepare v0.1.1 release for crates.io

- Rename `macros` crate to `libmarathon-macros` for better discoverability on crates.io
- Update all imports from `macros::` to `libmarathon_macros::`
- Add crates.io metadata (description, license, repository, homepage, etc.)
- Bump version to 0.1.1
- Add version requirement for libmarathon-macros dependency

crates/app/src/cube.rs

@@ -8,7 +8,7 @@ use uuid::Uuid;
 ///
 /// This component contains all the data needed for rendering a cube.
 /// The `#[synced]` attribute automatically handles network synchronization.
-#[macros::synced]
+#[libmarathon_macros::synced]
 pub struct CubeMarker {
     /// RGB color values (0.0 to 1.0)
     pub color_r: f32,