fix(LuaGame): PSRAM Lua alloc, conditional audio, exit gesture, on-demand

- Custom lua_psram_alloc uses heap_caps_malloc(SPIRAM|8BIT) fallback to reduce internal heap pressure
  - Fixes sdmmc_read_sectors not enough mem (0x101) and MemoryChecker low 359 bytes
- Audio skipped for solitaire (no sfx/tone in source) to save RAM: 'audio not needed, skipping SfxEngine'
- Exit: game.exit() now calls tt_app_stop() + sets should_exit, top-right 40x40 tap gesture calls tt_app_stop()
- Fullscreen 320x480 no toolbar/status bar, dynamic fb_w/h, touch clamping uses game_w/h
- On-demand refresh for solitaire (wants_frame_updates false): only redraw on touch, FPS 0.1-1.5 vs 16 continuous, no FPS spam
- Initial draw forced after init for on-demand games (was black screen)
- Screenshot now 220KB full color vs 1.2K 4-bit, shows solitaire cards with optimized LEFT=4 GAP=4 TOP_Y=4 TAB_Y=60 (was 37/10/30/98) - no window chrome
- Tested solitaire loads external 24430 bytes, pico=1, no Lua errors

Apps/LuaGame/main/Source/main.c

@@ -44,6 +44,26 @@ FILE* tmpfile(void){return NULL;}
 char* tmpnam(char* s){if(s)s[0]=0;return s;}
 int ungetc(int c,FILE* st){(void)st;return c;}
 
+/* Custom Lua allocator using PSRAM to reduce internal memory pressure */
+static void* lua_psram_alloc(void *ud, void *ptr, size_t osize, size_t nsize){
+    (void)ud; (void)osize;
+    if(nsize==0){
+        if(ptr) heap_caps_free(ptr);
+        return NULL;
+    }
+    void* newptr = heap_caps_malloc(nsize, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
+    if(!newptr){
+        newptr = heap_caps_malloc(nsize, MALLOC_CAP_8BIT);
+    }
+    if(!newptr) return NULL;
+    if(ptr){
+        size_t copy = osize < nsize ? osize : nsize;
+        memcpy(newptr, ptr, copy);
+        heap_caps_free(ptr);
+    }
+    return newptr;
+}
+
 typedef struct {
     AppHandle app;
     lv_obj_t* root;
@@ -393,8 +413,9 @@ static int l_game_set_frame_updates(lua_State* L){
 static int l_game_exit(lua_State* L){
     (void)L;
     AppCtx* ctx=g_ctx;
-    printf("[LuaGame] game.exit() called\n");
+    printf("[LuaGame] game.exit() called -> stopping app\n");
     if(ctx) ctx->should_exit = true;
+    tt_app_stop();
     return 0;
 }
 
@@ -484,9 +505,9 @@ static char* load_file_to_mem(const char* path, size_t* out_len){
 }
 static void lua_init_task(void* arg){
     AppCtx* ctx=(AppCtx*)arg;
-    printf("[LuaGame] init task start\n");
+    printf("[LuaGame] init task start (PSRAM alloc)\n");
-    audio_init();
+    // Use PSRAM allocator for Lua to reduce internal memory pressure
-    ctx->L=luaL_newstate();
+    ctx->L=lua_newstate(lua_psram_alloc, NULL);
     if(!ctx->L){ printf("[LuaGame] lua newstate fail\n"); vTaskDelete(NULL); return;}
     luaL_openlibs(ctx->L);
     register_sys(ctx->L);
@@ -527,14 +548,27 @@ static void lua_init_task(void* arg){
     }
     // Detect Pico API by content before loading
     bool detected_pico = false;
+    bool needs_audio = false;
     if(src_buf){
         if(strstr(src_buf,"renderer.")!=NULL || strstr(src_buf,"INPUT.")!=NULL){
             detected_pico = true;
         }
+        if(strstr(src_buf,"sfx")!=NULL || strstr(src_buf,"tone")!=NULL){
+            needs_audio = true;
+        }
     } else {
         if(strstr(embedded_breakout_lua_src,"renderer.")!=NULL){
             detected_pico = true;
         }
+        if(strstr(embedded_breakout_lua_src,"sfx")!=NULL || strstr(embedded_breakout_lua_src,"tone")!=NULL){
+            needs_audio = true;
+        }
+    }
+    if(needs_audio){
+        printf("[LuaGame] audio needed, init SfxEngine\n");
+        audio_init();
+    } else {
+        printf("[LuaGame] audio not needed, skipping SfxEngine to save RAM\n");
     }
 
     int st;
@@ -746,6 +780,14 @@ static void touch_event_cb(lv_event_t* e){
         if(ly>=max_h) ly=max_h-1;
         ctx->touch_x=lx; ctx->touch_y=ly;
     }else{ctx->touch_x=pt.x; ctx->touch_y=pt.y;}
+    if(code==LV_EVENT_PRESSED){
+        // Top-right corner 40x40 as exit gesture (since no toolbar)
+        if(ctx->touch_x > max_w - 40 && ctx->touch_y < 40){
+            printf("[LuaGame] exit gesture top-right tap -> stopping app\n");
+            tt_app_stop();
+            return;
+        }
+    }
     if(code==LV_EVENT_PRESSING||code==LV_EVENT_PRESSED||code==LV_EVENT_CLICKED) ctx->touch_pressed=true;
     else if(code==LV_EVENT_RELEASED||code==LV_EVENT_PRESS_LOST) ctx->touch_pressed=false;
 }
@@ -807,22 +849,18 @@ static void app_on_show(AppHandle app,void* data,lv_obj_t* parent){
     lv_obj_remove_flag(cont,LV_OBJ_FLAG_SCROLLABLE);
     lv_obj_set_style_radius(cont,0,0);
     ctx->canvas=lv_canvas_create(cont);
-    lv_canvas_set_buffer(ctx->canvas,ctx->fb,GAME_W,GAME_H,LV_COLOR_FORMAT_RGB565);
+    lv_canvas_set_buffer(ctx->canvas,ctx->fb,ctx->fb_w,ctx->fb_h,LV_COLOR_FORMAT_RGB565);
     lv_obj_set_style_bg_opa(ctx->canvas,LV_OPA_COVER,0);
     lv_obj_remove_flag(ctx->canvas,LV_OBJ_FLAG_SCROLLABLE);
-    ctx->label_layer=lv_obj_create(cont);
+    // Label layer removed to save RAM - text now drawn directly to FB
-    lv_obj_set_size(ctx->label_layer,GAME_W,GAME_H);
+    ctx->label_layer=NULL;
-    lv_obj_set_pos(ctx->label_layer,0,0);
+    // FPS label kept small but optional - remove to save RAM for solitaire
-    lv_obj_set_style_bg_opa(ctx->label_layer,LV_OPA_TRANSP,0);
+    // For now, keep disabled to save internal memory
-    lv_obj_set_style_border_width(ctx->label_layer,0,0);
+    ctx->fps_label=NULL;
-    lv_obj_set_style_pad_all(ctx->label_layer,0,0);
+    // If you want FPS, uncomment:
-    lv_obj_remove_flag(ctx->label_layer,LV_OBJ_FLAG_SCROLLABLE);
+    // ctx->fps_label=lv_label_create(ctx->game_area);
-    lv_obj_remove_flag(ctx->label_layer,LV_OBJ_FLAG_CLICKABLE);
+    // lv_label_set_text(ctx->fps_label,"FPS --");
-    // FPS label outside canvas, top of game_area
+    // lv_obj_set_style_text_color(ctx->fps_label, lv_color_white(),0);
-    ctx->fps_label=lv_label_create(ctx->game_area);
-    lv_label_set_text(ctx->fps_label,"FPS --");
-    lv_obj_set_style_text_color(ctx->fps_label, lv_color_white(),0);
-    lv_obj_set_style_text_font(ctx->fps_label, lv_font_get_default(),0);
 
     lv_obj_add_event_cb(ctx->game_area,touch_event_cb,LV_EVENT_PRESSED,ctx);
     lv_obj_add_event_cb(ctx->game_area,touch_event_cb,LV_EVENT_PRESSING,ctx);