ui: drop the clipboard/paste JSON buttons from Cards and custom files (v2.5.1)

- Cards and Custom files now expose only Export to file (JSON download) and
  Import from file; the Export-as-JSON / Paste & import / Import-JSON-from-
  clipboard buttons and their paste textareas are gone
- import feedback moves to a transient status line (new ioStatus helper);
  cardsImport/pysimCustomImport no longer read the clipboard
- Network simulation parameters: note under the operator form listing the
  scenarios that use the MCC/MNC (EPS/2G attach and SMS received write real
  LAI/RAI/TAI; cold boot, service lost, limited service and roaming denied
  write dummy files keeping the PLMN; churn/CB/AUTHENTICATE do not use it)
- i18n: removed-button entries dropped, note added EN/RU; help EN/RU updated
- guard tests for the button set and the note; SW cache simple-v196

frontend/help.html

@@ -313,7 +313,7 @@
 			<tr><td class="py-1 px-2">PSK key</td><td class="py-1 px-2">SCP81 HTTP OTA: 32 hex chars (16 bytes) for the PSK TLS listener, picked by the identity the card presents</td></tr>
 		</tbody>
 	</table>
-	<p class="text-sm mb-3">The <strong>SCP81</strong> column shows whether the preset supplies a usable PSK pair: <strong>&#10003;</strong> (green) — identity and key set; <strong>&#9888;</strong> (amber) — only one of the two, so the listener ignores the preset; <strong>&mdash;</strong> — no PSK. PSK identity and key must be set together. <strong>Edit</strong> loads a preset into the form (the Add button becomes <strong>Save</strong>; <strong>Cancel</strong> clears it) so fields can be changed without re-entering the card; <strong>Remove</strong> deletes the row. Presets can be shared with <strong>Export as JSON</strong> / <strong>Export to file</strong> and restored with <strong>Import from file</strong>, <strong>Paste &amp; import</strong>, or <strong>Import JSON from clipboard</strong>. The selected card preset auto-fills the Secured Packet form; edits are pushed into a running SCP81 listener automatically.</p>
+	<p class="text-sm mb-3">The <strong>SCP81</strong> column shows whether the preset supplies a usable PSK pair: <strong>&#10003;</strong> (green) — identity and key set; <strong>&#9888;</strong> (amber) — only one of the two, so the listener ignores the preset; <strong>&mdash;</strong> — no PSK. PSK identity and key must be set together. <strong>Edit</strong> loads a preset into the form (the Add button becomes <strong>Save</strong>; <strong>Cancel</strong> clears it) so fields can be changed without re-entering the card; <strong>Remove</strong> deletes the row. Presets can be shared with <strong>Export to file</strong> and restored with <strong>Import from file</strong>. The selected card preset auto-fills the Secured Packet form; edits are pushed into a running SCP81 listener automatically.</p>
 </section>
 
 <section class="mb-10">
@@ -436,7 +436,7 @@
 
 
 		<h4 id="custom-files" class="font-medium mb-1">Custom files</h4>
-	<p class="text-sm mb-3">Add files that pySim&rsquo;s model does not cover. A custom file always has a full path rooted at <strong>MF</strong> or an ADF (<strong>ADF.USIM</strong>, <strong>ADF.ISIM</strong>): pick the root, type the <strong>parent DF</strong> path (the root itself, a standard DF known from the file-manager tree, or a custom DF &mdash; any depth, with suggestions while you type; a parent that has not been seen in the tree yet stays valid and is marked <code class="font-mono text-sm">⚠</code>), the 4-hex <strong>FID</strong> and an alias (<code class="font-mono text-sm">EF.&hellip;</code>/<code class="font-mono text-sm">DF.&hellip;</code>; the prefix decides whether the entry is an EF or a DF). The canonical path removes the old ambiguity where the same file could be described both relatively and absolutely. Added files appear in the File manager tree; each row has <strong>Edit</strong> (path + alias; changing a DF&rsquo;s path re-points its child entries &mdash; the button becomes <strong>Save</strong>, <strong>Cancel</strong> aborts) and <strong>Delete</strong> (deleting a DF also deletes its child entries after a confirmation). The list persists in <code class="font-mono text-sm">localStorage</code> and can be shared with <strong>Export as JSON</strong> / <strong>Export to file</strong> / <strong>Import</strong>; legacy relative paths (e.g. <code class="font-mono text-sm">a153/4954</code>) are resolved on load, unresolvable ones are dropped and reported in the list.</p>
+	<p class="text-sm mb-3">Add files that pySim&rsquo;s model does not cover. A custom file always has a full path rooted at <strong>MF</strong> or an ADF (<strong>ADF.USIM</strong>, <strong>ADF.ISIM</strong>): pick the root, type the <strong>parent DF</strong> path (the root itself, a standard DF known from the file-manager tree, or a custom DF &mdash; any depth, with suggestions while you type; a parent that has not been seen in the tree yet stays valid and is marked <code class="font-mono text-sm">⚠</code>), the 4-hex <strong>FID</strong> and an alias (<code class="font-mono text-sm">EF.&hellip;</code>/<code class="font-mono text-sm">DF.&hellip;</code>; the prefix decides whether the entry is an EF or a DF). The canonical path removes the old ambiguity where the same file could be described both relatively and absolutely. Added files appear in the File manager tree; each row has <strong>Edit</strong> (path + alias; changing a DF&rsquo;s path re-points its child entries &mdash; the button becomes <strong>Save</strong>, <strong>Cancel</strong> aborts) and <strong>Delete</strong> (deleting a DF also deletes its child entries after a confirmation). The list persists in <code class="font-mono text-sm">localStorage</code> and can be shared with <strong>Export to file</strong> / <strong>Import from file</strong>; legacy relative paths (e.g. <code class="font-mono text-sm">a153/4954</code>) are resolved on load, unresolvable ones are dropped and reported in the list.</p>
 
 <section class="mb-10">
 	<h2 id="proactive-uicc" class="text-xl font-semibold mb-3 border-b border-gray-300 dark:border-slate-700 pb-1">8. Phone simulator</h2>