handshake-capture-c6 v1.0.4: persist captured BSSIDs, PCAP EAPOL recount

- /cap_bssids.txt append on save; handshakeLoadPersistedBssids after SD mount
- Boot order: SD then load file then first WiFi scan (reds match SD)
- Pre-save walk of in-memory PCAP counting EAPOL-Key frames
- SD_AppendLine / SD_ForEachLine; drop g_sd_ready clear on write fail
- README + MUST_DO updates

Made-with: Cursor

handshake-capture-c6/handshake-capture-c6.ino

@@ -117,15 +117,17 @@ void setup() {
   Set_Backlight(100);
   Lvgl_Init();
 
-  // WiFi + scan before SD: shared SPI with LCD; radio init can affect first SD.begin timing.
+  // WiFi up before SD (shared SPI); first scan only after persistence load so reds match SD file.
   handshakeCaptureInit();
-  WiFiScanner_Refresh();
 
-  HANDSHAKE_LOGLN("[SETUP] mounting SD after WiFi scan");
+  HANDSHAKE_LOGLN("[SETUP] mounting SD after WiFi init");
   if (!SD_Init()) {
     Ui_SetWifiStatus("SD: no card");
+    WiFiScanner_Refresh();
   } else {
     Ui_SetWifiStatus("SD OK");
+    handshakeLoadPersistedBssids();
+    WiFiScanner_Refresh();
   }
 
   captureState = STATE_SCANNING;