refactor(log): migra core/input i core/audio a Log::

- gamepad_manager.cpp (12 logs): connect/disconnect com a info,
  errors d'open/init com a error, warning per BD no carregada.
- key_config.cpp (5 logs): error per arxius malformats, info
  per al recompte de bindings carregats.
- gamepad_bindings.cpp (4 logs): error/info anàleg.
- audio_effects.cpp (2 errors de format).
- sound_effects_config.cpp (3 logs): warn quan no hi ha presets,
  error de parse.

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

source/core/audio/audio_effects.cpp

@@ -5,10 +5,10 @@
 #include <cmath>
 #include <cstdint>
 #include <cstring>
-#include <iostream>
 #include <vector>
 
 #include "core/audio/jail_audio.hpp"
+#include "utils/log.hpp"
 
 namespace AudioEffects {
 
@@ -46,11 +46,11 @@ namespace AudioEffects {
             } else if (spec.format == SDL_AUDIO_U8) {
                 bytes_per_sample = 1;
             } else {
-                std::cerr << "AudioEffects: format de so no suportat (només U8 o S16)\n";
+                Log::error("AudioEffects", "format de so no suportat (només U8 o S16)");
                 return false;
             }
             if (spec.channels < 1 || spec.channels > 2) {
-                std::cerr << "AudioEffects: el so ha de ser mono o estèreo\n";
+                Log::error("AudioEffects", "el so ha de ser mono o estèreo");
                 return false;
             }