Remove all coins except Palladium

coins.py keeps only Coin and the Palladium classes. The Bitcoin base class is
folded into Palladium. COIN now defaults to Palladium.

Tests and fixtures of the other coins are removed. test_blocks.py and
test_transactions.py are simplified: one test each, fed by the palladium
fixtures.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/test_blocks.py

@@ -30,37 +30,11 @@ from binascii import unhexlify
 
 import pytest
 
-from electrumx.lib import coins
 from electrumx.lib.coins import Coin
 from electrumx.lib.hash import hex_str_to_hash
 from electrumx.lib.util import subclasses
 
-
-def _does_coin_require_testcase(coin: Coin) -> bool:
-    if coin.NET != 'mainnet':
-        return False
-    # legacy whitelist: these coins do not have tests. FIXME
-    if coin in [
-        coins.BitcoinCash,
-        coins.Viacoin,
-        coins.Argentum,
-        coins.FairCoin,
-        coins.Einsteinium,
-        coins.Crown,
-        coins.Monaize,
-        coins.Bitbay,
-        coins.Fujicoin,
-        coins.Neblio,
-        coins.Bitzeny,
-        coins.Sibcoin,
-        coins.CanadaeCoin,
-        coins.Auroracoin,
-    ]:
-        return False
-    return True
-
-
-coin_classes_all = set([coin for coin in subclasses(Coin) if _does_coin_require_testcase(coin)])
+coin_classes_all = set([coin for coin in subclasses(Coin) if coin.NET == 'mainnet'])
 coin_classes_tested = set()
 
 BLOCKS_DIR = os.path.join(
@@ -69,15 +43,15 @@ BLOCKS_DIR = os.path.join(
 # Find testcases
 blocks = []
 
-for name in os.listdir(BLOCKS_DIR):
+for name in sorted(os.listdir(BLOCKS_DIR)):
     try:
         name_parts = name.split("_")
         coin = Coin.lookup_coin_class(name_parts[0], name_parts[1])
-        if _does_coin_require_testcase(coin):
+        if coin.NET == 'mainnet':
             coin_classes_tested.add(coin)
         with open(os.path.join(BLOCKS_DIR, name)) as f:
             blocks.append((coin, json.load(f)))
-    except Exception as e:
+    except Exception:
         blocks.append(pytest.fail(name))
 
 
@@ -92,11 +66,7 @@ def test_block(block_details):
     raw_block = unhexlify(block_info['block'])
     block = coin.block(raw_block, block_info['height'])
 
-    try:
-        assert coin.header_hash_rev(
-            block.header) == hex_str_to_hash(block_info['hash'])
-    except ImportError as e:
-        pytest.skip(str(e))
+    assert coin.header_hash_rev(block.header) == hex_str_to_hash(block_info['hash'])
     assert (coin.header_prevhash_rev(block.header)
             == hex_str_to_hash(block_info['previousblockhash']))
     assert len(block_info['tx']) == len(block.transactions)