feat: warn when the equipped card and the selected preset disagree (v3.8.0)

Autoselection normally keeps the SCP80/RAM preset in step with the card, so
the mismatch is easy to miss.  Both views now carry an amber banner above the
preset selector (the existing warning style - no new Tailwind classes):

- the equipped card matches no preset: "The equipped card <ICCID> does not
  match any card preset - the selected preset may belong to another card.
  Add it in the Cards tab (From card)"; with no presets at all the banner says
  so instead;
- a preset is selected but it is not the equipped card's: a softer line naming
  the matching preset ("check that its keys and counters belong to this card").

`spPresetWarning(iccid, presets, selectedIdx)` is pure (unit-tested with the
ICCID forms the store accepts: digits, spaced, raw EF hex), `spPresetWarningRender`
fills both banners and runs on every card-state poll, preset load, preset
selection and page init.  No card session or an unreadable ICCID shows nothing
(the card-iccid gating already explains that state); the banner warns only -
it never blocks a send (preparing a packet for another card stays possible).

Tests: frontend/tests/preset_warning.test.js (5), the card-state/preset
harnesses stub the DOM-bound renderer.  sw cache simple-v336.

frontend/help.html

@@ -339,7 +339,7 @@
 </section>
 <section class="mb-10">
 	<h2 id="cards" class="text-xl font-semibold mb-3 border-b border-gray-300 dark:border-slate-700 pb-1">4. Cards tab</h2>
-	<p class="mb-2">Stores card presets on the server (<code class="font-mono text-sm">~/.pysim-simple-server/card_presets.json</code>; <code class="font-mono text-sm">--card-presets</code> overrides it) so the Secured Packet view can auto-fill keys and parameters, the SCP81 HTTP OTA listener can look up PSK keys, and the SCP80 counters an operation consumed are persisted with the operation itself &mdash; a closed tab or a second browser window can no longer lose an increment. A preset carries <strong>one keyset per key version</strong> (the <code class="font-mono text-sm">b8..b5</code> nibble of KIc/KID, TS 102 225 &sect;5.1.2/A.2): KIc and KID of a keyset must carry the same version (01&ndash;0F; A.2 rejects a mismatch), and each key version has its own counter on the card (Annex A.1), so counters are tracked per keyset. The list is loaded when the PWA connects and can be exported/imported as JSON (the import also takes presets exported by older builds, flat or keyset-shaped). Cards is a top-level tab. When the card is equipped its EF.ICCID is read and the preset with the same ICCID is selected automatically in both SCP80 views. The form groups the fields into two bordered blocks: <strong>SCP80 (GSM 03.48, ETSI TS 102 225)</strong> (KIc/KID, SPI1/SPI2, the ISD/UICC RFM/ADF RFM TARs, counter and keys) and <strong>SCP81 (HTTP OTA)</strong> (the PSK identity/key pair with the key-selection note). The optional <strong>ADM</strong> field sits in the top row and is stored for later use by the file manager. The header shows gray <strong>SCP80</strong>/<strong>SCP81</strong> markers and a key glyph on the ADM badge when the preset matching the equipped card's ICCID has those settings filled in.</p>
+	<p class="mb-2">Stores card presets on the server (<code class="font-mono text-sm">~/.pysim-simple-server/card_presets.json</code>; <code class="font-mono text-sm">--card-presets</code> overrides it) so the Secured Packet view can auto-fill keys and parameters, the SCP81 HTTP OTA listener can look up PSK keys, and the SCP80 counters an operation consumed are persisted with the operation itself &mdash; a closed tab or a second browser window can no longer lose an increment. A preset carries <strong>one keyset per key version</strong> (the <code class="font-mono text-sm">b8..b5</code> nibble of KIc/KID, TS 102 225 &sect;5.1.2/A.2): KIc and KID of a keyset must carry the same version (01&ndash;0F; A.2 rejects a mismatch), and each key version has its own counter on the card (Annex A.1), so counters are tracked per keyset. The list is loaded when the PWA connects and can be exported/imported as JSON (the import also takes presets exported by older builds, flat or keyset-shaped). Cards is a top-level tab. When the card is equipped its EF.ICCID is read and the preset with the same ICCID is selected automatically in both SCP80 views; when the equipped card matches <strong>no</strong> preset &mdash; or the selected preset belongs to another card &mdash; both SCP80/RAM views show an amber warning above the preset selector. The form groups the fields into two bordered blocks: <strong>SCP80 (GSM 03.48, ETSI TS 102 225)</strong> (KIc/KID, SPI1/SPI2, the ISD/UICC RFM/ADF RFM TARs, counter and keys) and <strong>SCP81 (HTTP OTA)</strong> (the PSK identity/key pair with the key-selection note). The optional <strong>ADM</strong> field sits in the top row and is stored for later use by the file manager. The header shows gray <strong>SCP80</strong>/<strong>SCP81</strong> markers and a key glyph on the ADM badge when the preset matching the equipped card's ICCID has those settings filled in.</p>
 	<table class="w-full text-sm mb-3 border-collapse">
 		<thead><tr class="border-b border-gray-300 dark:border-slate-700"><th class="text-left py-1 px-2">Field</th><th class="text-left py-1 px-2">Description</th></tr></thead>
 		<tbody>