feat: Add host sydpc

My, this is a lot TwT.  Much work was batched as part of the transition from
guix-rebound to nixos-testbed/sydpc.

- Discord/Vesktop module & config.
- Syncthing setup.
- Assorted Emacs changes.
- Waybar config.
- Niri config.
- Steam config.
- Some MPD.
- Stylix config.
- Files/Impermanence things.
- Enable Ghostty.
- God knows what else.

modules/home/users/crumb/waybar/src/cycle_notifications.clj

@@ -0,0 +1,31 @@
+#!/usr/bin/env bb
+
+(ns cycle-notifications
+  (:require [babashka.process :as p]
+            [clojure.string :as str]
+            [cheshire.core :as json]))
+
+(defn get-mode []
+  (case (:out (p/shell {:out :string} "swaync-client -D"))
+    "true" :dnd
+    "false" :default))
+
+#_
+(get-mode)
+
+(defn toggle! []
+  (p/shell {:out nil} "swaync-client -d")
+  ;; Update Waybar.
+  (p/shell "pkill -SIGRTMIN+2 waybar"))
+
+(defn status []
+  (-> (case (:out (p/shell {:out :string} "swaync-client -D"))
+        "false" {:text "" :tooltip "Notify"}
+        "true" {:text "" :tooltip "Do not disturb"})
+      json/generate-string
+      println))
+
+(defn -main [& args]
+  (case (first args)
+    "toggle" (toggle!)
+    nil (status)))