docs: help restored to the UI (Cards/SCP81 sections), READMEs updated

The help pages had no SCP81 section and documented Cards as a 3.2 subsection
of the SCP80 tab. They now mirror the UI: 3 SCP80 (3.1 Secured Packet, 3.2
RAM), 4 Cards tab, 5 SCP81 tab (5.1 Listener, 5.2 Scripts), with the
following sections renumbered (6 Card reader, 7 Profiler, 8 Phone simulator,
9 Server, 10 Compatibility) and the TERMINAL PROFILE range corrected to bytes
1-39 (TS 102 223 5.2 + TS 31.111 5.2). The SCP81 tab and its sub-pills set
their own help anchors; a new test asserts every help anchor used by the UI
exists in help.html. READMEs: seven top-level tabs, SCP80 two pills, Cards
fields/buttons/SCP81 column, SCP81 modes (PSK TLS / pass-through / capture),
PSK pairs from presets, Scripts page and resume semantics. SW cache
otaman-v178.

frontend/index.html

@@ -7792,6 +7792,7 @@ function scp81SwitchSubtab(name) {
 	document.getElementById('scp81-sub-scripts').classList.toggle('hidden', name !== 'scripts');
 	if (name === 'scripts') { scriptsRender(); scriptsRebuildSelect(); }
 	else { scp81ModeChanged(); scp81StatusRefresh(); }
+	setHelpAnchor(name === 'scripts' ? 'scp81-scripts' : 'scp81-listener');
 }
 
 function scp81Msg(text, cls) {
@@ -8449,6 +8450,8 @@ function scp81Enter() {
 	scriptsRender();
 	scp81StatusRefresh();
 	scp81LogRefresh();
+	setHelpAnchor(document.getElementById('scp81-sub-scripts').classList.contains('hidden')
+		? 'scp81-listener' : 'scp81-scripts');
 	if (_scp81Timer) clearInterval(_scp81Timer);
 	_scp81Timer = setInterval(() => {
 		if (document.getElementById('tab-scp81').classList.contains('hidden')) return;