Add SD history UI and pin remap

- Add SD history chart + download listing to web UI
- Use HSPI for SD and fix SD pin mapping
- Swap role/OLED control pins and update role detection
- Update README pin mapping and SD/history docs

src/main.cpp

@@ -603,6 +603,7 @@ void setup() {
   g_boot_ms = millis();
   g_role = detect_role();
   init_device_ids(g_short_id, g_device_id, sizeof(g_device_id));
+  display_set_role(g_role);
   if (SERIAL_DEBUG_MODE) {
 #ifdef ARDUINO_ARCH_ESP32
     serial_debug_printf("boot: reset_reason=%d", static_cast<int>(esp_reset_reason()));
@@ -615,7 +616,6 @@ void setup() {
   display_init();
   time_rtc_init();
   time_try_load_from_rtc();
-  display_set_role(g_role);
   display_set_self_ids(g_short_id, g_device_id);
 
   if (g_role == DeviceRole::Sender) {