refactor(log): migra els subsistemes restants i elimina iostream

Acaba la migració dels std::cout/cerr a Log::*:

- core/locale, core/ui/ui_config, core/rendering/{screen,text,gif,
  surface, sprite/animated_sprite, sdl3gpu/*}.
- game/{options, debug_config, editor/editor_config, levels/level_manager,
  map/{map,tilemap,paint_layer}, entities/entity_manager_loadlevel}.

Severitats coherents: warns per a configs absents amb fallback,
errors per a YAML malformat o E/S fallida, infos per a estats.

Resultat:
- 0 occurrences de std::cout/std::cerr a source/.
- Cap #include <iostream> orfà (eliminat de surface.cpp).
- Output funcional idèntic al històric; AEE_LOG filtra (ex.
  `AEE_LOG=warn` només mostra warnings, `AEE_LOG=*:warn,Tag:info`
  combina globals i overrides).

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

source/core/locale/locale.cpp

@@ -1,11 +1,11 @@
 #include "core/locale/locale.hpp"
 
 #include <fstream>
-#include <iostream>
 #include <string>
 
 #include "core/resources/resource_helper.hpp"
 #include "external/fkyaml_node.hpp"
+#include "utils/log.hpp"
 
 namespace {
 
@@ -36,7 +36,7 @@ auto Locale::get() -> Locale& {
 void Locale::load(const std::string& file_path) {
     auto bytes = Resource::Helper::loadFile(file_path);
     if (bytes.empty()) {
-        std::cerr << "Locale: no s'ha pogut obrir " << file_path << '\n';
+        Log::error("Locale", "no s'ha pogut obrir {}", file_path);
         return;
     }
 
@@ -46,15 +46,15 @@ void Locale::load(const std::string& file_path) {
         auto yaml = fkyaml::node::deserialize(begin, end);
         strings_.clear();
         flatten(yaml, "", strings_);
-        std::cout << "Locale: " << strings_.size() << " traduccions des de " << file_path << '\n';
+        Log::info("Locale", "{} traduccions des de {}", strings_.size(), file_path);
     } catch (const std::exception& e) {
-        std::cerr << "Locale: error parsejant " << file_path << ": " << e.what() << '\n';
+        Log::error("Locale", "error parsejant {}: {}", file_path, e.what());
     }
 }
 
 auto Locale::text(const std::string& key) const -> std::string {
     auto it = strings_.find(key);
     if (it != strings_.end()) { return it->second; }
-    std::cerr << "Locale: clau no trobada: " << key << '\n';
+    Log::warn("Locale", "clau no trobada: {}", key);
     return key;
 }