afegit suport Emscripten/WebAssembly al build system

- CMakeLists.txt: branca EMSCRIPTEN amb SDL3 via FetchContent, preload de data/
  config/ i gamecontrollerdb.txt, WebGL2, EMSCRIPTEN_BUILD define i sortida .html.
  Exclou sdl3gpu_shader (no soportat a WebGL2) i el pack_tool en wasm.
- Makefile: target wasm via Docker emscripten/emsdk, build a build/wasm i
  sortida a dist/wasm (.html .js .wasm .data).
- director.cpp: createSystemFolder utilitza MEMFS en wasm (sense pwd.h/unistd.h),
  executable_path buit, dev-mode forçat (filesystem preload, no pack), windowed.
- screen.cpp: initShaders és no-op en wasm (SDL3 GPU no suportat a WebGL2).
- global_inputs.cpp: handleQuit és no-op en wasm (no es pot eixir del joc).
- Director::handleEvent ignora SDL_EVENT_QUIT en wasm.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

source/core/system/director.cpp

@@ -40,7 +40,7 @@
 #include "game/editor/map_editor.hpp"  // Para MapEditor
 #endif
 
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__EMSCRIPTEN__)
 #include <pwd.h>
 #endif
 
@@ -48,12 +48,17 @@
 Director::Director() {
     std::cout << "Game start" << '\n';
 
+#ifdef __EMSCRIPTEN__
+    // En Emscripten els assets estan al root del filesystem virtual (/data, /config)
+    executable_path_ = "";
+#else
     // Obtiene la ruta del ejecutable
     std::string base = SDL_GetBasePath();
     if (!base.empty() && base.back() == '/') {
         base.pop_back();
     }
     executable_path_ = base;
+#endif
 
     // Crea la carpeta del sistema donde guardar datos
     createSystemFolder("jailgames");
@@ -83,7 +88,7 @@ Director::Director() {
     // Preparar ruta al pack (en macOS bundle está en Contents/Resources/)
     std::string pack_path = executable_path_ + PREFIX + "/resources.pack";
 
-#ifdef RELEASE_BUILD
+#if defined(RELEASE_BUILD) && !defined(__EMSCRIPTEN__)
     // ============================================================
     // RELEASE BUILD: Pack-first architecture
     // ============================================================
@@ -141,6 +146,12 @@ Director::Director() {
     Options::setConfigFile(Resource::List::get()->get("config.yaml"));  // NOLINT(readability-static-accessed-through-instance)
     Options::loadFromFile();
 
+#ifdef __EMSCRIPTEN__
+    // A la versió web el navegador gestiona la finestra: res de fullscreen ni zoom.
+    Options::video.fullscreen = false;
+    Options::window.zoom = 1;
+#endif
+
     // Configura la ruta y carga los presets de PostFX
     Options::setPostFXFile(Resource::List::get()->get("postfx.yaml"));  // NOLINT(readability-static-accessed-through-instance)
     Options::loadPostFXFromFile();
@@ -168,7 +179,7 @@ Director::Director() {
     Screen::get()->setNotificationsEnabled(true);
 
     // Special handling for gamecontrollerdb.txt - SDL needs filesystem path
-#ifdef RELEASE_BUILD
+#if defined(RELEASE_BUILD) && !defined(__EMSCRIPTEN__)
     // In release, construct the path manually (not from Asset which has empty executable_path)
     std::string gamecontroller_db = executable_path_ + PREFIX + "/gamecontrollerdb.txt";
     Input::init(gamecontroller_db);
@@ -192,7 +203,7 @@ Director::Director() {
     std::cout << "\n";  // Fin de inicialización de sistemas
 
     // Inicializa el sistema de localización (antes de Cheevos que usa textos traducidos)
-#ifdef RELEASE_BUILD
+#if defined(RELEASE_BUILD) && !defined(__EMSCRIPTEN__)
     {
         // En release el locale está en el pack, no en el filesystem
         std::string locale_key = Resource::List::get()->get(Options::language + ".yaml");  // NOLINT(readability-static-accessed-through-instance)
@@ -205,7 +216,7 @@ Director::Director() {
 #endif
 
     // Special handling for cheevos.bin - also needs filesystem path
-#ifdef RELEASE_BUILD
+#if defined(RELEASE_BUILD) && !defined(__EMSCRIPTEN__)
     std::string cheevos_path = system_folder_ + "/cheevos.bin";
     Cheevos::init(cheevos_path);
 #else
@@ -244,6 +255,12 @@ Director::~Director() {
 
 // Crea la carpeta del sistema donde guardar datos
 void Director::createSystemFolder(const std::string& folder) {  // NOLINT(readability-convert-member-functions-to-static)
+#ifdef __EMSCRIPTEN__
+    // En Emscripten utilitzem MEMFS (no persistent entre sessions).
+    // No cal crear directoris: MEMFS els crea automàticament en escriure-hi.
+    system_folder_ = "/config/" + folder;
+    return;
+#else
 #ifdef _WIN32
     system_folder_ = std::string(getenv("APPDATA")) + "/" + folder;
 #elif __APPLE__
@@ -295,6 +312,7 @@ void Director::createSystemFolder(const std::string& folder) {  // NOLINT(readab
             }
         }
     }
+#endif  // __EMSCRIPTEN__
 }
 
 // Carga la configuración de assets desde assets.yaml
@@ -390,10 +408,13 @@ auto Director::iterate() -> SDL_AppResult {
 
 // SDL_AppEvent: despatxa un event a l'escena activa
 auto Director::handleEvent(const SDL_Event& event) -> SDL_AppResult {
+#ifndef __EMSCRIPTEN__
+    // A la versió web no tenim event de quit del navegador
     if (event.type == SDL_EVENT_QUIT) {
         SceneManager::current = SceneManager::Scene::QUIT;
         return SDL_APP_SUCCESS;
     }
+#endif
 
     if (active_scene_) {
         active_scene_->handleEvent(event);