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/sd_logger.cpp

@@ -5,6 +5,7 @@
 #include <time.h>
 
 static bool g_sd_ready = false;
+static SPIClass *g_sd_spi = nullptr;
 
 static const char *fault_text(FaultType fault) {
   switch (fault) {
@@ -43,7 +44,20 @@ void sd_logger_init() {
     g_sd_ready = false;
     return;
   }
-  g_sd_ready = SD.begin(PIN_SD_CS);
+  if (!g_sd_spi) {
+    g_sd_spi = new SPIClass(HSPI);
+  }
+  g_sd_spi->begin(PIN_SD_SCK, PIN_SD_MISO, PIN_SD_MOSI, PIN_SD_CS);
+  g_sd_ready = SD.begin(PIN_SD_CS, *g_sd_spi);
+  if (SERIAL_DEBUG_MODE) {
+    if (g_sd_ready) {
+      uint8_t type = SD.cardType();
+      uint64_t size = SD.cardSize();
+      Serial.printf("sd: ok type=%u size=%llu\n", static_cast<unsigned>(type), static_cast<unsigned long long>(size));
+    } else {
+      Serial.println("sd: init failed");
+    }
+  }
 }
 
 bool sd_logger_is_ready() {