qa: port 12 wallet/mining tests to python3 and fix three framework blockers

Ports qa/rpc-tests from 6 python3 files to 18. Ran every ported test against
the freshly built v1.3.0 dragonxd. Results, honestly:

  PASS (1)            getblocktemplate_proposals.py
  NOT APPLICABLE (7)  wallet.py, walletbackup.py, wallet_protectcoinbase.py,
                      wallet_listnotes.py, wallet_mergetoaddress.py,
                      getblocktemplate.py, wallet_shieldcoinbase.py
  BLOCKED (4)         wallet_sapling, wallet_nullifiers, wallet_persistence,
                      wallet_treestate

The "not applicable" seven are inherited Zcash/Hush-era tests that exercise
features DragonX deliberately removed. They assume transparent t->t value
transfer, but ASSETCHAINS_PRIVATE=1 (hush_utils.h:1826) makes sendtoaddress
and sendmany consensus-refuse; they assume Sprout joinsplits, which are gone
from the RPC layer entirely; and they hardcode Bitcoin economics (10 coin/block,
100-block maturity) against DragonX's 3 DRGX and COINBASE_MATURITY=1. They are
ported and left in place rather than deleted, but they cannot pass on this chain
without being rewritten around z_shieldcoinbase/autoshield.

Three framework fixes in test_framework/util.py, each of which broke every
multi-node test:
  - initialize_chain() passed -connect=0, and init.cpp soft-sets -listen=0 when
    -connect is present, so cache node0 never opened its p2p port and nodes 1-3
    could never sync to it -- initialize_chain() hung forever in sync_blocks().
    Now passes -listen=1 -bind=127.0.0.1 -dnsseed=0 explicitly (an explicit arg
    beats SoftSetBoolArg) while keeping the cache nodes off the public network.
  - cache cleanup removed files from <datadir> when dragonxd writes them one
    level deeper into the net-specific <datadir>/regtest.
  - set_node_times() did print("..." + t) with t an int -> TypeError.
  - default binary paths corrected to src/dragonxd and src/dragonx-cli.

The four BLOCKED tests are blocked by a daemon assert, not by the port; see the
follow-up commit/report on BLOCK_VALID_CONTEXT.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FU87LdsJZiZkfq1eXubpeo

qa/rpc-tests/wallet_persistence.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # Copyright (c) 2016-2024 The Hush developers
 # Copyright (c) 2018 The Zcash developers
 # Distributed under the GPLv3 software license, see the accompanying
@@ -13,6 +13,29 @@ from test_framework.util import (
 )
 from decimal import Decimal
 
+def get_value_pool(pools, pool_id):
+    """
+    Return the valuePools entry with the given id, or None if this chain does
+    not have that pool. DragonX's getblockchaininfo only reports the Sapling
+    pool (no Sprout history exists on this chain), so the pools list can no
+    longer be indexed positionally the way the upstream test did.
+    """
+    for pool in pools:
+        if pool['id'] == pool_id:
+            return pool
+    return None
+
+def assert_pool_values(pools, sprout_value, sapling_value):
+    sprout = get_value_pool(pools, 'sprout')
+    if sprout is not None:
+        assert_equal(sprout['chainValue'], sprout_value)
+    else:
+        # No Sprout pool at all is the same statement as "the Sprout pool holds nothing"
+        assert_equal(sprout_value, Decimal('0'))
+    sapling = get_value_pool(pools, 'sapling')
+    assert_true(sapling is not None, "Sapling value pool missing from getblockchaininfo")
+    assert_equal(sapling['chainValue'], sapling_value)
+
 class WalletPersistenceTest (BitcoinTestFramework):
 
     def setup_chain(self):
@@ -20,8 +43,20 @@ class WalletPersistenceTest (BitcoinTestFramework):
         initialize_chain_clean(self.options.tmpdir, 3)
 
     def setup_network(self, split=False):
+        # -listen=1/-bind: the framework's start_node() passes -connect=0, and DragonX (like
+        # Bitcoin) reacts to -connect by soft-setting -listen=0. A non-listening node can never
+        # accept the "addnode 127.0.0.1:<port>" that connect_nodes_bi() issues, so without this
+        # the three nodes stay isolated and sync_all() spins forever. -bind keeps the listener on
+        # loopback so a regtest node never becomes reachable from the public internet.
         self.nodes = start_nodes(3, self.options.tmpdir,
             extra_args=[[
+                '-listen=1',
+                '-bind=127.0.0.1',
+                # -dns=0: DragonX appends node1..node10.dragonx.is to -addnode for every chain
+                # named DRAGONX (hush_utils.h), and -connect=0 does not suppress -addnode. Without
+                # this a regtest node dials the LIVE DragonX network and is fed mainnet headers.
+                # The addnode calls connect_nodes_bi() makes use literal IPs, so they still work.
+                '-dns=0',
                 '-nuparams=5ba81b19:100', # Overwinter
                 '-nuparams=76b809bb:201', # Sapling
             ]] * 3)
@@ -69,12 +104,11 @@ class WalletPersistenceTest (BitcoinTestFramework):
 
         # Verify shielded balance
         assert_equal(self.nodes[0].z_getbalance(sapling_addr), Decimal('20'))
-        
+
         # Verify size of shielded pools
         pools = self.nodes[0].getblockchaininfo()['valuePools']
-        assert_equal(pools[0]['chainValue'], Decimal('0'))  # Sprout
-        assert_equal(pools[1]['chainValue'], Decimal('20')) # Sapling
-        
+        assert_pool_values(pools, Decimal('0'), Decimal('20'))
+
         # Restart the nodes
         stop_nodes(self.nodes)
         wait_bitcoinds()
@@ -82,8 +116,7 @@ class WalletPersistenceTest (BitcoinTestFramework):
 
         # Verify size of shielded pools
         pools = self.nodes[0].getblockchaininfo()['valuePools']
-        assert_equal(pools[0]['chainValue'], Decimal('0'))  # Sprout
-        assert_equal(pools[1]['chainValue'], Decimal('20')) # Sapling
+        assert_pool_values(pools, Decimal('0'), Decimal('20'))
 
         # Node 0 sends some shielded funds to Node 1
         dest_addr = self.nodes[1].z_getnewaddress('sapling')