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",