Convert all projects to PlatformIO

- JC3636W518 sketches: pioarduino 51.03.05 (Arduino core 3.0.5), ESP32-S3
  16MB QIO / OPI PSRAM, vendor libs via lib_extra_dirs, per-project lv_conf.h
- display_gif_embedded uses default_16MB.csv (firmware 3.4 MB > huge_app)
- elm327_wifi_bridge: espressif32 6.10.0 on esp32dev, pinned lib_deps
- elmulator: library in lib/, one env per example, duplicate copies removed
- .ino -> src/main.cpp, headers/lv_conf.h -> include/

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2-Program Example/Demo_Arduino/sd/src/main.cpp

@@ -0,0 +1,76 @@
+#include <Arduino.h>
+#include "pincfg.h"
+
+#include "SD_MMC.h"
+// #include "FS.h"
+
+void listDir(fs::FS &fs, const char *dirname, uint8_t levels) {
+  Serial.printf("Listing directory: %s\n", dirname);
+
+  File root = fs.open(dirname);
+  if (!root) {
+    Serial.println("Failed to open directory");
+    return;
+  }
+  if (!root.isDirectory()) {
+    Serial.println("Not a directory");
+    return;
+  }
+
+  File file = root.openNextFile();
+  while (file) {
+    if (file.isDirectory()) {
+      Serial.print("  DIR : ");
+      Serial.println(file.name());
+      if (levels) {
+        listDir(fs, file.path(), levels - 1);
+      }
+    } else {
+      Serial.print("  FILE: ");
+      Serial.print(file.name());
+      Serial.print("  SIZE: ");
+      Serial.println(file.size());
+    }
+    file = root.openNextFile();
+  }
+}
+
+void setup() {
+  delay(200);
+  Serial.begin(115200);
+
+  // Configure the SDMMC host
+  SD_MMC.setPins(SD_MMC_CLK_PIN, SD_MMC_CMD_PIN, SD_MMC_D0_PIN, SD_MMC_D1_PIN, SD_MMC_D2_PIN, SD_MMC_D3_PIN);
+
+  if (!SD_MMC.begin()) {
+    Serial.println("Card Mount Failed");
+    return;
+  }
+
+  uint8_t cardType = SD_MMC.cardType();
+  if (cardType == CARD_NONE) {
+    Serial.println("No SD card attached");
+    return;
+  }
+
+  Serial.println("SD Card initialized successfully.");
+
+  Serial.print("SD_MMC Card Type: ");
+  if (cardType == CARD_MMC) {
+    Serial.println("MMC");
+  } else if (cardType == CARD_SD) {
+    Serial.println("SDSC");
+  } else if (cardType == CARD_SDHC) {
+    Serial.println("SDHC");
+  } else {
+    Serial.println("UNKNOWN");
+  }
+
+  uint64_t cardSize = SD_MMC.cardSize() / (1024 * 1024);
+  Serial.printf("SD_MMC Card Size: %lluMB\n", cardSize);
+
+  listDir(SD_MMC, "/", 0);
+}
+
+void loop() {
+}