P2a: eight-bar arrangement with four editable sections

crates/zhila-protocol/src/lib.rs

@@ -208,6 +208,16 @@ pub enum Command {
         core: String,
         boundaries: Vec<f32>,
     },
+    SelectSection {
+        index: u8,
+    },
+    ClearSection {
+        index: u8,
+    },
+    CopySection {
+        from: u8,
+        to: u8,
+    },
     Undo,
     Redo,
     /// Journal-only: a core was imported through the binary path.
@@ -263,6 +273,10 @@ pub enum Event {
     CoreFaces {
         core: CoreSummary,
     },
+    Arrangement {
+        sections: Vec<Pattern>,
+        active: u8,
+    },
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
@@ -305,6 +319,8 @@ pub struct State {
     pub transport: TransportState,
     pub veins: Vec<VeinState>,
     pub pattern: Pattern,
+    pub arrangement: Vec<Pattern>,
+    pub active_section: u8,
     pub cores: Vec<CoreSummary>,
     pub audio: AudioInfo,
     pub journal_len: usize,