feat(version): report OS version on Windows and QuRT

Replace the previous unconditional 0 with a meaningful value
derived from each toolchain's compile-time macro:
- Windows uses _WIN32_WINNT (0xMMmm) -> major.minor.
- QuRT uses __HEXAGON_ARCH__ (e.g. 66) -> 6.6, falling back to
  0 if the macro is absent.

Both go through version_tag_to_number for parity with the Linux,
Darwin, Cygwin, and NuttX branches.

Signed-off-by: Nuno Marques <n.marques21@hotmail.com>

src/lib/version/version.c

@@ -35,6 +35,7 @@
 
 #include "build_git_version.h"
 
+#include <stdio.h>
 #include <string.h>
 
 #if !defined(CONFIG_CDCACM_PRODUCTID)
@@ -300,9 +301,7 @@ uint32_t px4_board_version(void)
 
 uint32_t px4_os_version(void)
 {
-#if defined(__PX4_QURT) || defined(__PX4_WINDOWS)
-	return 0;
-#elif defined(__PX4_LINUX) || defined(__PX4_DARWIN) || defined(__PX4_CYGWIN)
+#if defined(__PX4_LINUX) || defined(__PX4_DARWIN) || defined(__PX4_CYGWIN)
 	struct utsname name;
 
 	if (uname(&name) == 0) {
@@ -320,6 +319,26 @@ uint32_t px4_os_version(void)
 		return 0;
 	}
 
+#elif defined(__PX4_WINDOWS)
+	// _WIN32_WINNT is the targeted Windows version, encoded as 0xMMmm
+	// (e.g. 0x0A00 → Windows 10.0). It is set by the toolchain.
+	char buf[16];
+	snprintf(buf, sizeof(buf), "%d.%d.0",
+		 (_WIN32_WINNT >> 8) & 0xFF,
+		 _WIN32_WINNT & 0xFF);
+	return version_tag_to_number(buf);
+#elif defined(__PX4_QURT)
+	// Hexagon clang sets __HEXAGON_ARCH__ to the DSP architecture revision
+	// (e.g. 66 for hexagonv66), which we map to a major.minor pair.
+#ifdef __HEXAGON_ARCH__
+	char buf[16];
+	snprintf(buf, sizeof(buf), "%d.%d.0",
+		 __HEXAGON_ARCH__ / 10,
+		 __HEXAGON_ARCH__ % 10);
+	return version_tag_to_number(buf);
+#else
+	return 0;
+#endif
 #elif defined(__PX4_NUTTX)
 	return version_tag_to_number(NUTTX_GIT_TAG_STR);
 #else