v3.19.0 (cont.): live fixtures; menu text match is case-insensitive by default

No test scripts have been authored yet, so the format is still free to
change - the menu-select text match is now case-insensitive by default
(menu labels are UI text; case_sensitive: true still forces an exact-case
match, and a miss on it names the case-insensitive candidates).

Verification against the live card's own bytes (captured 2026-10-04):
- the Annex A Variant 2 Cyrillic menu (ids 128..130) resolves by text and
  the case behaviour above is pinned ('кофе' -> item 130);
- the applet's SEND SHORT MESSAGE (alpha 'Отправка...', SMS-SUBMIT to
  +79332505884) pins the new alpha and sms checks and the run-log line.

docs/help/api updated; sw cache simple-v388 (help pages changed).
Tests: 819 frontend + 726 Python.

pysim_simple_server/testscript.py

@@ -281,7 +281,10 @@ def _normalise_params(kind, p):
             if mode not in ('exact', 'contains'):
                 raise ScriptError('menu-select: mode must be exact or contains')
             out['mode'] = mode
-            out['case_sensitive'] = bool(p.get('case_sensitive', True))
+            # Menu labels are UI text: case-insensitive by default (no test
+            # scripts predate this choice); `case_sensitive: true` forces an
+            # exact-case match.
+            out['case_sensitive'] = bool(p.get('case_sensitive', False))
         if not out:
             raise ScriptError('menu-select: item_id or text is required')
         if 'item_id' in out and 'text' in out: