v1.2.0 — Linux Flasher, Kali Creator, fixed flashing & counterfeit detection

New features:
- Linux Flasher tab: download+decompress+flash pipeline for RPi OS, Ubuntu,
  Debian, Fedora, Kali, DietPi, Alpine, Arch ARM with built-in image catalog
- Kali Creator tab: 4 sub-tabs for USB/SD, VM creation, Docker/Podman
  container pulls, and cloud image downloads
- DownloadManager: async downloads with resume support and speed tracking
- Decompressor: streaming .xz (xz-embedded), .gz (zlib), .zip decompression
- ImageCatalog: built-in catalog + remote fetch from rpi-imager JSON endpoint
- SevenZipExtractor: QProcess wrapper for 7z.exe with progress parsing
- Bundled xz-embedded third-party library for native XZ decompression

Bug fixes:
- Fixed VirtualDisk::flashToDisk() — added FSCTL_ALLOW_EXTENDED_DASD_IO,
  FSCTL_LOCK_VOLUME, FSCTL_DISMOUNT_VOLUME, 32MB aligned buffers,
  WriteFile retry logic (3 attempts), FlushFileBuffers before close
- Fixed VirtualDisk::captureFromDisk() with same improvements
- Fixed ImagingTab::onFlashIso() — now populates targetVolumeLetters from
  disk snapshot so IsoFlasher can properly lock/dismount volumes
- Fixed SD card counterfeit detection false positives:
  - Changed from write-one-read-one to write-all-then-read-all algorithm
    to properly detect NAND address wrapping on fake cards
  - Added volume lock/dismount before probing to prevent filesystem
    interference (journal writes, metadata updates)
  - Added FSCTL_ALLOW_EXTENDED_DASD_IO for probes near end of disk
  - Fixed overly aggressive vendor string check — USB card readers
    legitimately report "USB"/"Mass Storage", no longer flagged
  - Added handle re-open between write and verify phases to defeat
    USB reader hardware cache
- README: documented how to unlock the secret menu, added new feature docs

third_party/xz-embedded/xz_crc64.c

@@ -0,0 +1,41 @@
+/*
+ * XZ decompressor - CRC64
+ *
+ * Based on xz-embedded by Lasse Collin (public domain).
+ * CRC64 with polynomial 0xC96C5795D7870F42 (ECMA-182).
+ */
+
+#include "xz_private.h"
+
+uint64_t xz_crc64_table[256];
+
+void xz_crc64_init(void)
+{
+    static int done = 0;
+    uint64_t i, j, r;
+
+    if (done)
+        return;
+
+    for (i = 0; i < 256; ++i) {
+        r = i;
+        for (j = 0; j < 8; ++j)
+            r = (r >> 1) ^ (UINT64_C(0xC96C5795D7870F42) & ~((r & 1) - 1));
+        xz_crc64_table[i] = r;
+    }
+
+    done = 1;
+}
+
+uint64_t xz_crc64(const uint8_t *buf, size_t size, uint64_t crc)
+{
+    crc = ~crc;
+
+    while (size > 0) {
+        crc = xz_crc64_table[(crc ^ *buf) & 0xFF] ^ (crc >> 8);
+        ++buf;
+        --size;
+    }
+
+    return ~crc;
+}