plugins/coq-nvim: remove settings.xdg option

It's removed & deprecated in upstream's v2 plugin.

plugins/by-name/coq-nvim/default.nix

@@ -35,17 +35,13 @@ lib.nixvim.plugins.mkNeovimPlugin {
       with types; maybeRaw (either bool (enum [ "shut-up" ]))
     ) "Auto-start or shut up";
 
-    xdg = lib.mkOption {
-      type = types.bool;
-      default = true;
-      description = "Use XDG paths. May be required when installing coq with Nix.";
-    };
-
     keymap.recommended = defaultNullOpts.mkBool true "Use the recommended keymaps";
 
     completion.always = defaultNullOpts.mkBool true "Always trigger completion on keystroke";
   };
 
+  imports = [ ./deprecation.nix ];
+
   extraConfig = cfg: {
     extraPlugins = lib.mkIf cfg.installArtifacts [ cfg.artifactsPackage ];
 

plugins/by-name/coq-nvim/deprecation.nix

@@ -0,0 +1,19 @@
+{
+  lib,
+  config,
+  options,
+  ...
+}:
+let
+  cfg = config.plugins.coq-nvim;
+  opts = options.plugins.coq-nvim;
+in
+{
+  assertions = lib.nixvim.mkAssertions "plugins.coq-nvim" [
+    # TODO: Added 2026-06-15; remove after 27.11
+    {
+      assertion = !(cfg.settings ? xdg);
+      message = "xdg has been removed in v2. The field is ignored — delete it from `${opts.settings}`.";
+    }
+  ];
+}

tests/test-sources/plugins/by-name/coq-nvim/default.nix

@@ -8,7 +8,6 @@
       enable = true;
 
       settings = {
-        xdg = true;
         auto_start = true;
         keymap.recommended = true;
         completion.always = true;