IBD/sync speedups: parallel RandomX pre-verify, adaptive dbcache, P2P download fixes

- Parallel RandomX PoW pre-verification pool (CCheckQueue) run ahead of the serial
  connect; consensus-neutral (inline CheckRandomXSolution fallback still verifies
  anything not pre-verified). New -randomxverifythreads (default = -par).
- Adaptive dbcache: default sizes the UTXO/coins cache to most of RAM and shrinks
  under memory pressure, always leaving a reserve free; -dbcache pins a fixed value.
- P2P block download: bounded socket recv-drain loop (tlsmanager); frontier-block
  reassignment to break head-of-line stalls (-blockreassigntimeout); ProcessGetData
  serves a bounded batch of blocks per pass instead of one (fixes the serve-side
  one-block-per-tick throttle that caps download network-wide).
- assumeutxo: dumptxoutset RPC + LoadSnapshot machinery + AssumeutxoData chainparams.
- Signed bootstrap verification (util/bootstrap-dragonx.sh, util/sign-bootstrap.md).
- gtest: RandomX pre-verify consensus-equivalence test + UTXO-snapshot round-trip;
  revived the gtest harness (Makefile.am include fix, Makefile.gtest.include).

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

src/Makefile.gtest.include

@@ -4,65 +4,59 @@ TESTS += hush-gtest
 bin_PROGRAMS += hush-gtest
 
 # tool for generating our public parameters
+# NOTE: the original test list used an invalid automake form (comment after a trailing
+# backslash, and `zcash_gtest_SOURCES +=` with no prior `=`), which is why the whole
+# gtest harness was disabled via a `#include`. Minimal valid set: the harness + the
+# UTXO-snapshot round-trip test. Re-add other gtest sources here as they are revived.
 hush_gtest_SOURCES = \
 	gtest/main.cpp \
 	gtest/utils.cpp \
-	gtest/test_checktransaction.cpp \
-	gtest/json_test_vectors.cpp \
-        gtest/json_test_vectors.h \
-	gtest/test_wallet_zkeys.cpp \
-# These tests are order-dependent, because they
-# depend on global state (see #1539)
-if ENABLE_WALLET
-zcash_gtest_SOURCES += \
-	wallet/gtest/test_wallet_zkeys.cpp
-endif
-zcash_gtest_SOURCES += \
-	gtest/test_tautology.cpp \
-	gtest/test_deprecation.cpp \
-	gtest/test_equihash.cpp \
-	gtest/test_httprpc.cpp \
-	gtest/test_keys.cpp \
-	gtest/test_keystore.cpp \
-	gtest/test_noteencryption.cpp \
-	gtest/test_mempool.cpp \
-	gtest/test_merkletree.cpp \
-	gtest/test_metrics.cpp \
-	gtest/test_miner.cpp \
-	gtest/test_pow.cpp \
-	gtest/test_random.cpp \
-	gtest/test_rpc.cpp \
-	gtest/test_sapling_note.cpp \
-	gtest/test_transaction.cpp \
-	gtest/test_transaction_builder.cpp \
-	gtest/test_upgrades.cpp \
-	gtest/test_validation.cpp \
-	gtest/test_circuit.cpp \
-	gtest/test_txid.cpp \
-	gtest/test_libzcash_utils.cpp \
-	gtest/test_proofs.cpp \
-	gtest/test_pedersen_hash.cpp \
-	gtest/test_checkblock.cpp \
-	gtest/test_zip32.cpp
-if ENABLE_WALLET
-zcash_gtest_SOURCES += \
-	wallet/gtest/test_wallet.cpp
-endif
+	gtest/test_utxosnapshot.cpp \
+	gtest/test_randomx_preverify.cpp
 
 hush_gtest_CPPFLAGS = $(AM_CPPFLAGS) -DMULTICORE -fopenmp -DBINARY_OUTPUT -DCURVE_ALT_BN128 -DSTATIC $(BITCOIN_INCLUDES)
 hush_gtest_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 
-hush_gtest_LDADD = -lgtest -lgmock $(LIBBITCOIN_SERVER) $(LIBBITCOIN_CLI) $(LIBBITCOIN_COMMON) $(LIBBITCOIN_UTIL) $(LIBBITCOIN_CRYPTO) $(LIBBITCOIN_UNIVALUE) $(LIBLEVELDB) $(LIBMEMENV) \
-  $(BOOST_LIBS) $(BOOST_UNIT_TEST_FRAMEWORK_LIB) $(LIBSECP256K1)
+# Mirror dragonxd_LDADD's working library set/order (the old list used a non-existent
+# $(LIBBITCOIN_UNIVALUE) so univalue was never linked, and omitted LIBHUSH/LIBRANDOMX/libcc).
+hush_gtest_LDADD = -lgtest -lgmock \
+  $(LIBBITCOIN_SERVER) \
+  $(LIBBITCOIN_COMMON) \
+  $(LIBUNIVALUE) \
+  $(LIBBITCOIN_UTIL) \
+  $(LIBBITCOIN_CRYPTO) \
+  $(LIBZCASH) \
+  $(LIBHUSH) \
+  $(LIBLEVELDB) \
+  $(LIBMEMENV) \
+  $(LIBSECP256K1) \
+  $(LIBRANDOMX)
 if ENABLE_WALLET
 hush_gtest_LDADD += $(LIBBITCOIN_WALLET)
 endif
 
-hush_gtest_LDADD += $(LIBZCASH_CONSENSUS) $(BDB_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(LIBZCASH) $(LIBZCASH_LIBS)
+hush_gtest_LDADD += \
+  $(BOOST_LIBS) \
+  $(BOOST_UNIT_TEST_FRAMEWORK_LIB) \
+  $(BDB_LIBS) \
+  $(SSL_LIBS) \
+  $(CRYPTO_LIBS) \
+  $(EVENT_PTHREADS_LIBS) \
+  $(EVENT_LIBS) \
+  $(LIBBITCOIN_CRYPTO) \
+  $(LIBZCASH_LIBS)
 
-hush_gtest_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) -static
+if TARGET_DARWIN
+hush_gtest_LDADD += libcc.dylib $(LIBSECP256K1)
+endif
+if TARGET_WINDOWS
+hush_gtest_LDADD += libcc.dll $(LIBSECP256K1)
+endif
+if TARGET_LINUX
+hush_gtest_LDADD += libcc.so $(LIBSECP256K1)
+endif
 
-hush_gtest_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) -static
+hush_gtest_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 hush-gtest-expected-failures: hush-gtest FORCE
 	./hush-gtest --gtest_filter=*DISABLED_* --gtest_also_run_disabled_tests