feat: add custom/disk-monitor waybar module with color-coded disk usage

waybar/.config/waybar/config.jsonc

@@ -25,6 +25,7 @@
         
        "modules-right": [
            "group/hardware",
+           "custom/disk-monitor",
            "pulseaudio",
            "bluetooth",
            "network",

waybar/.config/waybar/modules.json

@@ -88,6 +88,13 @@
 		"path": "/",
 		"on-click": "kitty btop"
 	}, 
+
+	// disk monitor (standalone, color-coded)
+	"custom/disk-monitor": {
+		"exec": "$HOME/.config/waybar/scripts/disk-monitor.sh --waybar",
+		"return-type": "json",
+		"interval": 60
+	},
 	
 	// memory
 	"memory": {

waybar/.config/waybar/scripts/disk-monitor.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+# disk-monitor.sh -- Waybar disk usage monitor
+# Outputs JSON for custom/disk-monitor module
+# Class: "good" (<80%), "warning" (80-90%), "critical" (>90%)
+
+set -euo pipefail
+
+# Target partition (default: root)
+TARGET="${1:-/}"
+
+# Get disk usage percentage (strip % sign)
+USAGE=$(df --output=pcent "$TARGET" | tail -1 | tr -d '% ')
+
+# Determine icon and CSS class based on usage thresholds
+if [ "$USAGE" -ge 90 ]; then
+    CLASS="critical"
+    TOOLTIP="Disk $TARGET at ${USAGE}% - CRITICAL"
+elif [ "$USAGE" -ge 80 ]; then
+    CLASS="warning"
+    TOOLTIP="Disk $TARGET at ${USAGE}% - Warning"
+else
+    CLASS="good"
+    TOOLTIP="Disk $TARGET at ${USAGE}%"
+fi
+
+# Output JSON for waybar
+printf '{"text": " \uf4be %s%% ", "class": "%s", "alt": "%s", "tooltip": "%s"}\n' \
+    "$USAGE" "$CLASS" "disk-$CLASS" "$TOOLTIP"