Rebrand hush3 to DragonX and share RandomX dataset across mining threads

Minimal rebrand (see compliant-rebrand branch for full rebrand):
- Rename binaries: hushd/hush-cli/hush-tx → dragonxd/dragonx-cli/dragonx-tx
- Default to DRAGONX chain params without -ac_* flags (randomx, blocktime=36, private=1)
- Update configure.ac: AC_INIT([DragonX],[1.0.0])
- Update client version string and user-agent to /DragonX:1.0.0/
- Add chainparams.cpp with DRAGONX network parameters
- Update build.sh, miner.cpp, pow.cpp for DragonX
- Add bootstrap-dragonx.sh utility script
- Update .gitignore for release directory

Share single RandomX dataset across all mining threads:
- Add RandomXDatasetManager with readers-writer lock, reducing RAM from
  ~2GB per thread to ~2GB total plus ~2MB per thread for the VM scratchpad
- Add LogProcessMemory() diagnostic helper for Linux and Windows

src/clientversion.h

@@ -28,9 +28,9 @@
 // client versioning and copyright year
 //! These need to be macros, as clientversion.cpp's and bitcoin*-res.rc's voodoo requires it
 // Must be kept in sync with configure.ac , ugh!
-#define CLIENT_VERSION_MAJOR 3
-#define CLIENT_VERSION_MINOR 10
-#define CLIENT_VERSION_REVISION 5
+#define CLIENT_VERSION_MAJOR 1
+#define CLIENT_VERSION_MINOR 0
+#define CLIENT_VERSION_REVISION 0
 #define CLIENT_VERSION_BUILD 50
 
 //! Set to true for release, false for prerelease or test build
@@ -40,7 +40,7 @@
  * Copyright year (2009-this)
  * Todo: update this when changing our copyright comments in the source
  */
-#define COPYRIGHT_YEAR 2024
+#define COPYRIGHT_YEAR 2026
 
 #endif //HAVE_CONFIG_H