Add NIP-05 well-known endpoint

app/controllers/well_known_controller.rb

@@ -0,0 +1,16 @@
+class WellKnownController < ApplicationController
+  def nostr
+    http_status :unprocessable_entity and return if params[:name].blank?
+    domain = request.headers["X-Forwarded-Host"].presence || Setting.primary_domain
+    @user = User.where(cn: params[:name], ou: domain).first
+    http_status :not_found and return if @user.nil? || @user.nostr_pubkey.blank?
+
+    respond_to do |format|
+      format.json do
+        render json: {
+          names: { "#{@user.cn}": @user.nostr_pubkey }
+        }.to_json
+      end
+    end
+  end
+end