Reorganize dashboard UI with tabbed layout and improved status bars

Add tabbed navigation in right panel with "hosts | services" tabs to
better utilize vertical space. Hosts tab displays all available hosts
with blue selector bar (j/k navigation, Enter to switch). Services tab
shows services for currently selected host.

Status bar improvements:
- Move dashboard IP to top-right status bar (non-bold)
- Restructure bottom status bar with right-aligned build/agent versions
- Fix overflow crashes using saturating_sub for small terminal windows

Additional changes:
- Add HostsWidget with scroll handling and mouse click support
- Bold styling for currently active host
- Create render_content() methods to avoid nested blocks in tabs
- Display SMB share read/write mode in share listings

Cargo.lock

@@ -279,7 +279,7 @@ checksum = "a1d728cc89cf3aee9ff92b05e62b19ee65a02b5702cff7d5a377e32c6ae29d8d"
 
 [[package]]
 name = "cm-dashboard"
-version = "0.1.274"
+version = "0.1.276"
 dependencies = [
  "anyhow",
  "chrono",
@@ -301,7 +301,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-agent"
-version = "0.1.274"
+version = "0.1.275"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -325,7 +325,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-shared"
-version = "0.1.274"
+version = "0.1.275"
 dependencies = [
  "chrono",
  "serde",