crates/nuncio-gui/src/main.rs

@@ -2,16 +2,19 @@
 
 mod ipc;
 mod sandbox;
+mod view;
 
 use ipc::IpcBridge;
 use nuncio_core::EventBus;
+use view::GuiViewState;
 
 fn main() {
     let bus = EventBus::new();
     let state = IpcBridge::get_app_state(&bus);
+    let view_state = GuiViewState::default();
 
     println!(
-        "Nuncio GUI Desktop Shell Initialized: status={:?}, unread={}",
-        state.status, state.unread_count
+        "Nuncio GUI Desktop Shell Initialized: status={:?}, unread={}, active_folder={}",
+        state.status, state.unread_count, view_state.active_folder_id
     );
 }

crates/nuncio-gui/src/view.rs

@@ -0,0 +1,82 @@
+//! React/Vite Webview component layout model and state bindings.
+
+use nuncio_core::model::{Email, Folder};
+use serde::{Deserialize, Serialize};
+
+/// Frontend split-view layout state container.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct GuiViewState {
+    /// Available folders list.
+    pub folders: Vec<Folder>,
+    /// Active selected folder ID.
+    pub active_folder_id: String,
+    /// Loaded email message list.
+    pub messages: Vec<Email>,
+    /// Currently selected email ID for reading preview.
+    pub selected_message_id: Option<String>,
+    /// Dark mode UI theme preference flag.
+    pub dark_mode: bool,
+}
+
+impl GuiViewState {
+    /// Create a new default GUI view state.
+    pub fn new() -> Self {
+        Self {
+            folders: vec![
+                Folder {
+                    id: "inbox".to_string(),
+                    name: "Inbox".to_string(),
+                    total_messages: 5,
+                    unread_messages: 2,
+                },
+                Folder {
+                    id: "sent".to_string(),
+                    name: "Sent".to_string(),
+                    total_messages: 3,
+                    unread_messages: 0,
+                },
+            ],
+            active_folder_id: "inbox".to_string(),
+            messages: Vec::new(),
+            selected_message_id: None,
+            dark_mode: true,
+        }
+    }
+
+    /// Select active folder.
+    pub fn select_folder(&mut self, folder_id: &str) {
+        self.active_folder_id = folder_id.to_string();
+        self.selected_message_id = None;
+    }
+
+    /// Select active message preview.
+    pub fn select_message(&mut self, message_id: &str) {
+        self.selected_message_id = Some(message_id.to_string());
+    }
+}
+
+impl Default for GuiViewState {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn gui_view_state_navigation() {
+        let mut state = GuiViewState::default();
+
+        assert_eq!(state.active_folder_id, "inbox");
+        assert!(state.dark_mode);
+
+        state.select_folder("sent");
+        assert_eq!(state.active_folder_id, "sent");
+        assert!(state.selected_message_id.is_none());
+
+        state.select_message("msg-101");
+        assert_eq!(state.selected_message_id, Some("msg-101".to_string()));
+    }
+}