feat: next action suffix in the pending SELECT ITEM panel (v3.5.6)

The STK menu overlay's cached top menu showed the card-provided Items Next
Action Indicator (TS 102 223 8.24) as a gray suffix, but the pending
SELECT ITEM list the card returns mid-dialogue did not: the server already
attaches nai_name (via _parse_select_item), the panel just had its own row
markup without the suffix.

Both lists now render through stkMenuItemsHtml(items, handler) - identical
rows (id, text, optional gray suffix) with the per-list click callback
(stkMenuItemClick / stkSubItemClick).

stk_menu.test.js: the shared renderer (suffix only with nai_name, handler
in the row, null list) plus a call-site guard for both lists.

554 frontend / 421 Python green; version 3.5.6; sw cache simple-v259.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pysim-simple-server"
-version = "3.5.5"
+version = "3.5.6"
 description = "HTTP REST server wrapping pysim for the SIMple PWA"
 requires-python = ">=3.8"
 # pysim is a git-only dependency installed explicitly by setup.bat/setup.sh.