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/libmarathon/tests/sync_integration_headless.rs

@@ -70,7 +70,7 @@ use uuid::Uuid;
 // ============================================================================
 
 /// Simple position component for testing sync
-#[macros::synced]
+#[libmarathon_macros::synced]
 #[derive(Reflect, PartialEq)]
 #[reflect(Component)]
 struct TestPosition {
@@ -79,7 +79,7 @@ struct TestPosition {
 }
 
 /// Simple health component for testing sync
-#[macros::synced]
+#[libmarathon_macros::synced]
 #[derive(Reflect, PartialEq)]
 #[reflect(Component)]
 struct TestHealth {