feat(input): notifica connexio/desconnexio de mandos via Notifier

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

data/locale/ca.yaml

@@ -14,6 +14,8 @@ notification:
   postfx_on: "POSTPROCESSAT ACTIU"
   postfx_off: "POSTPROCESSAT INACTIU"
   locale_switched: "IDIOMA: {lang}"
+  gamepad_connected: "{name} CONNECTAT"
+  gamepad_disconnected: "{name} DESCONNECTAT"
 
 language:
   ca: "CATALA"

data/locale/en.yaml

@@ -13,6 +13,8 @@ notification:
   postfx_on: "POSTPROCESS ON"
   postfx_off: "POSTPROCESS OFF"
   locale_switched: "LANGUAGE: {lang}"
+  gamepad_connected: "{name} CONNECTED"
+  gamepad_disconnected: "{name} DISCONNECTED"
 
 language:
   ca: "CATALAN"