v3.25.3: the card's BIP commands during test runs

The runner's three FETCH/TR sites (the proactive-drain action, the
expectation, the cleanup drain) built every TERMINAL RESPONSE from the
script, so a card-announced OPEN CHANNEL during a run was answered
"performed successfully" without opening a channel - SEND DATA was
dropped and RECEIVE DATA returned nothing (silent data loss, broken
applet state).

_test_step_tr now routes 0x40-0x44 through _handle_bip_command: the
terminal answers for real, so the card's channels work inside a run.
The script keeps an escape hatch - a respond with `raw` TLVs or a
non-ok result wins (the applet error-path tests).

The BIP events flow during a run again for the channels the card
itself opened: _bip_data_available and _bip_flush_channel_events no
longer stop at the run guard (a channel only exists because the card
opened it) and the runner flushes the link events after each TR, so an
applet's own HTTP/BIP conversation completes inside a scripted run.
BIP control stays blocked (409).

Tests: the drain/expect/cleanup routing, the raw and non-ok-result
overrides, the run-time data-available and link events.  883 frontend
+ 873 Python; sw cache simple-v427.

tests/test_poll.py

@@ -185,11 +185,13 @@ class TestProactiveChainOwnership(unittest.TestCase):
     1100-command loop held _CARD_LOCK and blocked a run's start)."""
 
     def setUp(self):
-        self.saved = (S._TEST_RUNNING, S._server_ref, S._CARD_CONNECTED)
+        self.saved = (S._TEST_RUNNING, S._server_ref, S._CARD_CONNECTED,
+                      S._BIP_LINK_EVENTS, S._FLUSHING_CHANNEL_EVENTS)
         S._TEST_RUNNING = False
 
     def tearDown(self):
-        S._TEST_RUNNING, S._server_ref, S._CARD_CONNECTED = self.saved
+        (S._TEST_RUNNING, S._server_ref, S._CARD_CONNECTED,
+         S._BIP_LINK_EVENTS, S._FLUSHING_CHANNEL_EVENTS) = self.saved
 
     def _fetches(self, scc):
         return [a for a in scc.sent if a.lower().startswith('8012')]
@@ -238,6 +240,29 @@ class TestProactiveChainOwnership(unittest.TestCase):
             S._sim_resume_poll()
             timer.assert_not_called()
 
+    def test_data_available_flows_during_a_run(self):
+        # a BIP channel only exists because the card opened it: the event is
+        # the card's own conversation continuing, so it flows during a run
+        # (v3.25.3 - the card must not wait for the run to end)
+        ch = types.SimpleNamespace(peer_closed=False, rx=b'ABCD', id=1)
+        S._server_ref = types.SimpleNamespace(scc=object(), event_list=[0x09])
+        S._CARD_CONNECTED = True
+        S._TEST_RUNNING = True
+        with mock.patch.object(S, '_send_event_download') as send:
+            ok = S._bip_data_available(ch)
+        self.assertTrue(ok)
+        send.assert_called_once()
+        self.assertEqual(send.call_args[0][1], 0x09)
+
+    def test_link_events_are_taken_during_a_run(self):
+        # the queued link events describe the card's own channels: the flush
+        # no longer stops at the run guard (v3.25.3)
+        S._TEST_RUNNING = True
+        S._BIP_LINK_EVENTS = False
+        with mock.patch.object(S._BIP, 'take_pending_events') as take:
+            S._bip_flush_channel_events(None)
+        take.assert_called_once()
+
     def test_every_run_end_resumes_the_poll(self):
         # the two worker bodies, their two exception paths and the spawn
         # failure all call the helper