test(conformance): g4 keeps checking past an input typed at coordinates

An InputText that names no field aborts the analyzer, so the gate reports the
whole run as failed and checks none of the steps after it. 129 of the 485
recorded traces hold such a step.

Red at this commit: jq stops on a null selector and the gate reports FAIL.

conformance/testdata/generate.py

@@ -152,6 +152,17 @@ write_run(
     ],
 )
 
+# G4: an action typed at coordinates names no field. The step carries nothing
+# the gate can check, and it may not stop the gate checking the rest.
+write_run(
+    "g4-selectorless-input",
+    [
+        step(1, 600, login_screen("", ""), {"kind": "InputText", "text": REDACTED}),
+        step(2, 600, login_screen("[email protected]", ""), input_action("LoginPassword")),
+        step(3, 600, login_screen("[email protected]", "ledger123")),
+    ],
+)
+
 # G4: the same regression on a backend that records the typed value. The driver
 # appended the value twice to what the field already held, so the observed value
 # is not its own doubling and only the recorded text reveals it.