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.

docs/api.md

@@ -671,7 +671,8 @@ optional `src` - the device-identities source override),
 `event` (`event` name or hex + `fields`, optional `src` - the semantic event
 download for 0x03/0x0B/0x12/0x1D), `menu-select` (`item_id` 1-255, or `text` +
 `mode` `exact`/`contains` with an
-optional `case_sensitive` - the text is resolved against the card's cached
+optionally `case_sensitive: true` for an exact-case match, case-insensitive by
+default - the text is resolved against the card's cached
 SET UP MENU, which is refreshed whenever the card sends the menu), `file-write`
 (`path`, `data`, `mode` `auto`/`binary`/`record`, `record`), `file-read` (same,
 verifies `check.data`),