feat(emacs): Mark for application/pdf

modules/home/users/crumb/default-applications.nix

@@ -0,0 +1,20 @@
+{ config, lib, pkgs, ... }:
+
+let cfg = config.sydnix.users.crumb.default-applications;
+in {
+  options.sydnix.users.crumb.default-applications = {
+    enable = lib.mkEnableOption "Default mime-type applications";
+  };
+
+  config = lib.mkIf cfg.enable {
+    xdg.mimeApps = {
+      enable = true;
+      defaultApplications = {
+        "application/pdf" = [
+          "emacsclient.desktop"
+          "emacs.desktop"
+        ];
+      };
+    };
+  };
+}

modules/home/users/crumb/emacs.nix

@@ -152,5 +152,13 @@ in {
         ec = "emacsclient";
         em = "emacs";
       };
+
+      # Mark Emacs as a valid PDF reader.
+      xdg.mimeApps.associations.added = {
+        "application/pdf" = [
+          "emacsclient.desktop"
+          "emacs.desktop"
+        ];
+      };
     });
 }