handshake-capture-c6: SPI bus lock, SD v1.0.2 diagnostics, MUST_DO review

- SPI_Bus_Lock: serialize LCD + SD on shared SPI; pause display during SD
- SD_Init after WiFi scan; SD_IsReady gating; serial [SD]/[CAP] diagnostics
- MUST_DO_IMPROVEMENTS.md full firmware review backlog; README link
- Bump HANDSHAKE_FIRMWARE_VERSION to 1.0.2 (header)

Made-with: Cursor

handshake-capture-c6/HandshakeCapture.h

@@ -6,9 +6,36 @@
 #include <SD.h>
 
 /** Semantic version (Serial banner + support). */
-#define HANDSHAKE_FIRMWARE_VERSION "1.0.1"
+#define HANDSHAKE_FIRMWARE_VERSION "1.0.3"
 
-/** SD write only after this many EAPOL-Key frames (full WPA/WPA2 4-way). */
+#ifndef HANDSHAKE_DEBUG
+#define HANDSHAKE_DEBUG 0
+#endif
+
+#ifndef USE_SOFTAP
+#define USE_SOFTAP 0
+#endif
+
+#define HANDSHAKE_MIN_CHANNEL         1
+#define HANDSHAKE_MAX_CHANNEL         14
+#define HANDSHAKE_OBSERVE_DURATION_MS 8000UL
+#define HANDSHAKE_CAPTURE_TIMEOUT_MS  20000UL
+#define HANDSHAKE_CHANNEL_TIMEOUT_MS  150000UL
+#define HANDSHAKE_DEAUTH_BURST_COUNT  5
+#define HANDSHAKE_DEAUTH_BURST_DELAY_MS 2
+#define HANDSHAKE_MAX_OBSERVE_CYCLES  5
+#define HANDSHAKE_DEAUTH_GAP_AFTER_CLIENT_MS 80
+#define HANDSHAKE_DEAUTH_GAP_AFTER_SLOT_MS   120
+
+#if HANDSHAKE_DEBUG
+#define HANDSHAKE_LOGF(...)   Serial.printf(__VA_ARGS__)
+#define HANDSHAKE_LOGLN(msg)  Serial.println(msg)
+#else
+#define HANDSHAKE_LOGF(...)   do { } while (0)
+#define HANDSHAKE_LOGLN(msg)  do { } while (0)
+#endif
+
+/** Heuristic threshold only; frames are not validated as distinct 4-way steps. */
 #define HANDSHAKE_EAPOL_FRAMES 4
 
 // Two APs at once: less on-air contention, more time per target before rotating.
@@ -82,6 +109,8 @@ bool wasBssidCaptured(const uint8_t* bssid);
 void scanNetworksSortedByRSSI();
 void startMultiCapture();
 void stopCapture();
+bool isSupportedCaptureAuth(const String& encryption);
+bool isSupportedCaptureChannel(int channel);
 bool isCaptureable(int index);
 void handshakeCaptureLoop();
 int getCaptureableCount();