Merge fix/windows-cross-build into the v1.2.0 line

Brings the two mingw cross-compile build-system fixes (link-group via
AC_SUBST(LINK_GROUP_*), librustzcash staged-name normalization) onto the
v1.2.0 line that now carries Phases 1-2 of the code-hygiene remediation.
The two sides are disjoint (build-system files vs. src/wallet/rpc), so
this is a clean integration; the merged tree is re-verified to build for
Windows (Phase 1/2 source changes had only been built for Linux before).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/Makefile.am

@@ -489,7 +489,7 @@ if TARGET_WINDOWS
 dragonxd_SOURCES += bitcoind-res.rc
 endif
 
-dragonxd_LDADD = \
+dragonxd_LDADD = $(LINK_GROUP_START) \
   $(LIBBITCOIN_SERVER) \
   $(LIBCURL) \
   $(LIBBITCOIN_COMMON) \
@@ -527,6 +527,8 @@ if TARGET_LINUX
 dragonxd_LDADD += libcc.so $(LIBSECP256K1)
 endif
 
+dragonxd_LDADD += $(LINK_GROUP_END)
+
 # [+] Decker: use static linking for libstdc++.6.dylib, libgomp.1.dylib, libgcc_s.1.dylib
 if TARGET_DARWIN
 dragonxd_LDFLAGS += -static-libgcc
@@ -553,7 +555,7 @@ if TARGET_WINDOWS
 dragonx_cli_SOURCES += bitcoin-cli-res.rc
 endif
 
-dragonx_cli_LDADD = \
+dragonx_cli_LDADD = $(LINK_GROUP_START) \
 	$(LIBBITCOIN_CLI) \
 	$(LIBUNIVALUE) \
 	$(LIBBITCOIN_UTIL) \
@@ -566,8 +568,10 @@ dragonx_cli_LDADD = \
 	$(LIBBITCOIN_CRYPTO) \
 	$(LIBZCASH_LIBS)
 
+dragonx_cli_LDADD += $(LINK_GROUP_END)
+
 if ENABLE_WALLET
-wallet_utility_LDADD = \
+wallet_utility_LDADD = $(LINK_GROUP_START) \
 	libbitcoin_wallet.a \
 	$(LIBBITCOIN_COMMON) \
 	$(LIBBITCOIN_CRYPTO) \
@@ -579,6 +583,7 @@ wallet_utility_LDADD = \
 	$(LIBZCASH) \
 	$(LIBZCASH_LIBS)\
     $(LIBRANDOMX)
+wallet_utility_LDADD += $(LINK_GROUP_END)
 endif
 
 # hush-tx binary #
@@ -591,7 +596,7 @@ if TARGET_WINDOWS
 dragonx_tx_SOURCES += bitcoin-tx-res.rc
 endif
 
-dragonx_tx_LDADD = \
+dragonx_tx_LDADD = $(LINK_GROUP_START) \
   $(LIBUNIVALUE) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_UTIL) \
@@ -602,7 +607,7 @@ dragonx_tx_LDADD = \
   $(LIBZCASH_LIBS) \
   $(LIBRANDOMX)
 
-dragonx_tx_LDADD += $(BOOST_LIBS) $(CRYPTO_LIBS)
+dragonx_tx_LDADD += $(BOOST_LIBS) $(CRYPTO_LIBS) $(LINK_GROUP_END)
 
 # Zcash Protocol Primitives
 libzcash_a_SOURCES = \