Style command + GET RESPONSE pairs in the APDU list; bump to 1.15.0

- Pair members (a command ending '61 XX' and its GET RESPONSE, via the
  server-side response_for link) get a subtle slate row tint
  (--pair-row, themed: rgba(148,163,184,.12) dark / rgba(100,116,139,.15)
  light); hover/selected still take precedence.
- Paired GET RESPONSE rows are prefixed with '↳' marking them as a
  continuation of the previous command; orphaned GRs stay plain.
- GET RESPONSE label uses cat-gr class: muted color, weight 600 like
  other command names.
- Map view untouched (it skips GRs); detail view already shows
  "Response for".

Version 1.15.0, SW cache simtrace-analyser-v20.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.backends._legacy:_Backend"
 
 [project]
 name = "simtrace2-pysniff"
-version = "1.14.0"
+version = "1.15.0"
 description = "Python-based sniffing tool for SIMtrace2 hardware (SIM card communication sniffer)"
 readme = {file = "README.md", content-type = "text/markdown"}
 license = {text = "GPL-2.0-or-later"}