Simplify navigation and add vi-style keys

Major UI simplification and navigation improvements:

Changes:
- Removed panel selection concept entirely (no more Shift+Tab)
- Service selection always visible with blue highlighting
- Up/Down arrows now directly control service selection
- Added j/k vi-style navigation keys as alternatives to arrow keys
- Removed panel focus borders - all panels look uniform
- Service commands (s/S) work without panel focus requirements
- Updated keyboard shortcuts to reflect simplified navigation

Navigation:
- Tab: Switch hosts
- ↑↓/jk: Select service (always works)
- R: Rebuild host
- s: Start service
- S: Stop service
- q: Quit

The interface is now much simpler and more intuitive with direct service control.

Cargo.lock

@@ -270,7 +270,7 @@ checksum = "a1d728cc89cf3aee9ff92b05e62b19ee65a02b5702cff7d5a377e32c6ae29d8d"
 
 [[package]]
 name = "cm-dashboard"
-version = "0.1.31"
+version = "0.1.32"
 dependencies = [
  "anyhow",
  "chrono",
@@ -291,7 +291,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-agent"
-version = "0.1.31"
+version = "0.1.32"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -314,7 +314,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-shared"
-version = "0.1.31"
+version = "0.1.32"
 dependencies = [
  "chrono",
  "serde",