refactor(syncthing): Refactor syncthing modules

modules/nixos/deertopia/syncthing.nix

@@ -0,0 +1,47 @@
+{ config, lib, pkgs, ... }:
+
+let cfg = config.sydnix.deertopia.syncthing;
+in {
+  options.sydnix.deertopia.syncthing.enable =
+    lib.mkEnableOption "Syncthing, à la Deertopia";
+  config = lib.mkIf cfg.enable {
+    sydnix.syncthing = {
+      enable = true;
+      includeDevices = [
+        "guix-rebound"
+        "nixos-testbed"
+      ];
+      directories = {
+        "Music" = {
+          path = "/persist/vault/jellyfin/Music";
+          devices = [ "guix-rebound" ];
+          ignorePerms = true;
+        };
+        "org" = {
+          path = "/persist/deertopia.net/dav/org";
+          devices = [
+            "guix-rebound"
+            "nixos-testbed"
+          ];
+          ignorePerms = true;
+        };
+      };
+    };
+
+    # HACK: I don't understand the idioms of Unix file permissions.
+    # TODO: Consult molly for this shit TwT.
+    users.users.${config.services.syncthing.user}.extraGroups = [
+      "jellyfin"
+      "nginx"
+    ];
+
+    sydnix.deertopia.nginx.vhosts."syncthing".vhost = {
+      forceSSL = true;
+      enableACME = true;
+      locations."/" = {
+        # TODO: This should work if guiAddress already specifies a protocol.
+        proxyPass = "http://" + config.services.syncthing.guiAddress;
+      };
+    };
+  };
+}