chore: Add warning log for missing keyboard in selector

lib/fusuma/plugin/remap/keyboard_remapper.rb

@@ -302,10 +302,15 @@ def initialize(names = ["keyboard", "Keyboard", "KEYBOARD"])
           # If no device is found, it will wait for 3 seconds and try again
           # @return [Array<Revdev::EventDevice>]
           def select
+            displayed_no_keyboard = false
             loop do
               Fusuma::Device.reset # reset cache to get the latest device information
               devices = Fusuma::Device.all.select { |d| Array(@names).any? { |name| d.name =~ /#{name}/ } }
               if devices.empty?
+                unless displayed_no_keyboard
+                  MultiLogger.warn "No keyboard found: #{@names}"
+                  displayed_no_keyboard = true
+                end
                 wait_for_device
 
                 next

spec/fusuma/plugin/remap/keyboard_remapper_spec.rb

@@ -35,9 +35,10 @@
           allow(selector).to receive(:loop).and_yield
           allow(Fusuma::Device).to receive(:all).and_return([])
         end
-        it "wait for device" do
-          expect(selector).to receive(:loop).and_yield
+
+        it "wait for device, and logs warn message" do
           expect(selector).to receive(:wait_for_device)
+          expect(Fusuma::MultiLogger).to receive(:warn).with(/No keyboard found/)
           selector.select
         end
       end