Replace empty panels with offline host message for better UX

- Hide all system/backup/service panels when host is offline
- Show centered wake-up message with host status
- Display "Press 'w' to wake up host" if MAC address configured
- Provide clear visual indication when hosts are unreachable
- Improve user experience by removing confusing empty panels

Version 0.1.64

Cargo.lock

@@ -270,7 +270,7 @@ checksum = "a1d728cc89cf3aee9ff92b05e62b19ee65a02b5702cff7d5a377e32c6ae29d8d"
 
 [[package]]
 name = "cm-dashboard"
-version = "0.1.62"
+version = "0.1.63"
 dependencies = [
  "anyhow",
  "chrono",
@@ -292,7 +292,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-agent"
-version = "0.1.62"
+version = "0.1.63"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -315,7 +315,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-shared"
-version = "0.1.62"
+version = "0.1.63"
 dependencies = [
  "chrono",
  "serde",

agent/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-agent"
-version = "0.1.63"
+version = "0.1.64"
 edition = "2021"
 
 [dependencies]

dashboard/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard"
-version = "0.1.63"
+version = "0.1.64"
 edition = "2021"
 
 [dependencies]

dashboard/src/ui/mod.rs

@@ -558,6 +558,21 @@ impl TuiApp {
             ])
             .split(main_chunks[1]); // main_chunks[1] is now the content area (between title and statusbar)
 
+        // Check if current host is offline
+        let current_host_offline = if let Some(hostname) = self.current_host.clone() {
+            self.calculate_host_status(&hostname, metric_store) == Status::Offline
+        } else {
+            true // No host selected is considered offline
+        };
+
+        // If host is offline, render wake-up message instead of panels
+        if current_host_offline {
+            self.render_offline_host_message(frame, main_chunks[1]);
+            self.render_btop_title(frame, main_chunks[0], metric_store);
+            self.render_statusbar(frame, main_chunks[2]);
+            return;
+        }
+
         // Check if backup panel should be shown
         let show_backup = if let Some(hostname) = self.current_host.clone() {
             let host_widgets = self.get_or_create_host_widgets(&hostname);
@@ -811,6 +826,77 @@ impl TuiApp {
         }
     }
 
+    /// Render offline host message with wake-up option
+    fn render_offline_host_message(&self, frame: &mut Frame, area: Rect) {
+        use ratatui::layout::Alignment;
+        use ratatui::style::Modifier;
+        use ratatui::text::{Line, Span};
+        use ratatui::widgets::{Block, Borders, Paragraph};
+
+        // Get hostname for message
+        let hostname = self.current_host.as_ref()
+            .map(|h| h.as_str())
+            .unwrap_or("Unknown");
+
+        // Check if host has MAC address for wake-on-LAN
+        let has_mac = self.current_host.as_ref()
+            .and_then(|hostname| self.config.hosts.get(hostname))
+            .and_then(|details| details.mac_address.as_ref())
+            .is_some();
+
+        // Create message content
+        let mut lines = vec![
+            Line::from(Span::styled(
+                format!("Host '{}' is offline", hostname),
+                Style::default().fg(Theme::muted_text()).add_modifier(Modifier::BOLD),
+            )),
+            Line::from(""),
+        ];
+
+        if has_mac {
+            lines.push(Line::from(Span::styled(
+                "Press 'w' to wake up host",
+                Style::default().fg(Theme::primary_text()).add_modifier(Modifier::BOLD),
+            )));
+        } else {
+            lines.push(Line::from(Span::styled(
+                "No MAC address configured - cannot wake up",
+                Style::default().fg(Theme::muted_text()),
+            )));
+        }
+
+        // Create centered message
+        let message = Paragraph::new(lines)
+            .block(Block::default()
+                .borders(Borders::ALL)
+                .border_style(Style::default().fg(Theme::muted_text()))
+                .title(" Offline Host ")
+                .title_style(Style::default().fg(Theme::muted_text()).add_modifier(Modifier::BOLD)))
+            .style(Style::default().bg(Theme::background()).fg(Theme::primary_text()))
+            .alignment(Alignment::Center);
+
+        // Center the message in the available area
+        let popup_area = ratatui::layout::Layout::default()
+            .direction(Direction::Vertical)
+            .constraints([
+                Constraint::Percentage(40),
+                Constraint::Length(6),
+                Constraint::Percentage(40),
+            ])
+            .split(area)[1];
+
+        let popup_area = ratatui::layout::Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints([
+                Constraint::Percentage(25),
+                Constraint::Percentage(50),
+                Constraint::Percentage(25),
+            ])
+            .split(popup_area)[1];
+
+        frame.render_widget(message, popup_area);
+    }
+
     /// Parse MAC address string (e.g., "AA:BB:CC:DD:EE:FF") to [u8; 6]
     fn parse_mac_address(mac_str: &str) -> Result<[u8; 6], &'static str> {
         let parts: Vec<&str> = mac_str.split(':').collect();

shared/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-shared"
-version = "0.1.63"
+version = "0.1.64"
 edition = "2021"
 
 [dependencies]