docs: a refused envelope may carry no response packet (guide + help)

The alfa-dsa control-commands run showed the error case: an applet-level
refusal (envelope 6200 for an unknown command) carries no PoR at all, so
a por expectation on such a step can never match.  The authoring guide's
status-words section now states that a 62XX/63XX envelope does not
guarantee a response packet - other warning paths still deliver one (the
low-counter case arrives via SEND SHORT MESSAGE) - and that a step
expected to be refused should leave por at its "any" default or assert
"none"; help EN/RU notes the same.  docs/test-scripts.md only, no code
change; sw cache simple-v392 (help files are precached).

docs/test-scripts.md

@@ -54,6 +54,14 @@ secured data is exposed as `por.data`.  Assert such a response with `data`
 and leave `sw` empty; the step's `check.sw` still asserts the envelope
 exchange.
 
+A `62XX`/`63XX` envelope answer does not guarantee a response packet: an
+application that refuses at the envelope level (e.g. an applet answering
+`6200` to an unknown command) sends none, while other warning paths still
+deliver one (the low-counter case arrives via SEND SHORT MESSAGE).  For a
+step expected to be refused, leave `por` at its `"any"` default or assert
+`"por": "none"`; the run report's `PoR[…]` log line and `por` field show
+which happened.
+
 ### Worksheet 1 - RFM update → file change → REFRESH (full FCN)
 
 ```json