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/input/key_config.cpp

@@ -1,11 +1,11 @@
 #include "core/input/key_config.hpp"
 
 #include <fstream>
-#include <iostream>
 #include <string>
 
 #include "core/resources/resource_helper.hpp"
 #include "external/fkyaml_node.hpp"
+#include "utils/log.hpp"
 
 auto KeyConfig::get() -> KeyConfig& {
     static KeyConfig instance_;
@@ -15,7 +15,7 @@ auto KeyConfig::get() -> KeyConfig& {
 void KeyConfig::load(const std::string& file_path) {
     auto bytes = Resource::Helper::loadFile(file_path);
     if (bytes.empty()) {
-        std::cerr << "KeyConfig: no s'ha pogut obrir " << file_path << '\n';
+        Log::error("KeyConfig", "no s'ha pogut obrir {}", file_path);
         return;
     }
 
@@ -24,7 +24,7 @@ void KeyConfig::load(const std::string& file_path) {
         const auto* end = begin + bytes.size();
         auto yaml = fkyaml::node::deserialize(begin, end);
         if (!yaml.contains("keys") || !yaml["keys"].is_sequence()) {
-            std::cerr << "KeyConfig: falta la secció 'keys' a " << file_path << '\n';
+            Log::error("KeyConfig", "falta la secció 'keys' a {}", file_path);
             return;
         }
         bindings_.clear();
@@ -34,14 +34,14 @@ void KeyConfig::load(const std::string& file_path) {
             const auto CODE = entry["code"].get_value<std::string>();
             const SDL_Scancode SC = SDL_GetScancodeFromName(CODE.c_str());
             if (SC == SDL_SCANCODE_UNKNOWN) {
-                std::cerr << "KeyConfig: codi SDL desconegut '" << CODE << "' per id '" << ID << "'\n";
+                Log::warn("KeyConfig", "codi SDL desconegut '{}' per id '{}'", CODE, ID);
                 continue;
             }
             bindings_[ID] = SC;
         }
-        std::cout << "KeyConfig: " << bindings_.size() << " bindings des de " << file_path << '\n';
+        Log::info("KeyConfig", "{} bindings des de {}", bindings_.size(), file_path);
     } catch (const std::exception& e) {
-        std::cerr << "KeyConfig: error parsejant " << file_path << ": " << e.what() << '\n';
+        Log::error("KeyConfig", "error parsejant {}: {}", file_path, e.what());
     }
 }