feat: animated-QR transfer, Android reader, relative-locktime preservation, karen7 hermetic tests

tests/conftest.py

@@ -0,0 +1,18 @@
+"""Shared pytest fixtures.
+
+Guards every test against cross-file network pollution: several karen7
+regtest modules historically flipped ``electrum.constants.net`` to regtest at
+import time, which broke unrelated offline tests (e.g. the CLI controller
+suite) run in the same pytest process.
+"""
+
+import pytest
+from electrum import constants
+
+
+@pytest.fixture(autouse=True)
+def _restore_network():
+    """Snapshot ``constants.net`` before each test and restore it after."""
+    prev = constants.net
+    yield
+    constants.net = prev