feat(desktop): consolidate declarative workstation profile

Capture desktop-specific system, session, Noctalia, and Pi integration alongside shared laptop support. Retire obsolete X11 configuration and make package ownership explicit for repeatable Decman deployments.

system-config/config/user/desktop/noctalia/90-machine.toml

@@ -1,17 +1,21 @@
 # Desktop-specific shell layout and hardware telemetry.
-# Pi Status Bridge is installed locally from ~/projects/pi-status-bridge.
+# Pi Status Bridge is installed from ~/projects/pi-gui on both hosts.
 [plugins]
 enabled = ["alex/system-status", "alex/pi-status-bridge", "alex/knowledge-lookup"]
 
 [widget.pi-status]
 type = "alex/pi-status-bridge:bridge"
 
+[shell.screenshot]
+confirm_region = true
+directory = "/home/alex/downloads"
+
 [bar.main]
 position = "bottom"
 layer = "top"
 scale = 0.95
 capsule_radius = 5
-center = ["group:g3", "notifications"]
+center = ["pi-status", "knowledge-lookup", "group:g3", "notifications", "screenshot"]
 end = ["group:g2", "group:g6", "group:g1", "session"]
 font_weight = 400
 margin_ends = 0
@@ -19,11 +23,11 @@ padding = 0
 panel_overlap = 3
 radius = 0
 shadow = false
-# Keep the desktop status bar visible and reserve its screen edge.
-auto_hide = false
+# Auto-hide while reserving the screen edge; reveal the bar at its edge.
+auto_hide = true
 smart_auto_hide = false
 reserve_space = true
-start = ["tray", "group:g4", "privacy"]
+start = ["tray", "group:g4"]
 thickness = 39
 widget_spacing = 10
 
@@ -56,7 +60,7 @@ radius = 5.0
 enabled = true
 fill = "surface_variant"
 id = "g4"
-members = ["pi-status", "cpu", "temp", "ram", "gpu", "gpu_temp", "disk"]
+members = ["cpu", "temp", "ram", "gpu", "gpu_temp", "disk"]
 opacity = 1.0
 padding = 6.0
 
@@ -89,3 +93,8 @@ width = 880
 [system.monitor]
 # GPU polling is disabled by Noctalia by default; enable it for the RTX 3090 widgets.
 gpu_poll_seconds = 2.0
+
+# The desktop's Hypridle listener provides a five-minute input-dismissable black
+# OLED overlay. Keep Noctalia from issuing a competing DPMS screen-off action.
+[idle.behavior.screen-off]
+enabled = false