net-sim: network-condition simulation in the Phone tab (v2.5.0)

Server (pysim_simple_server/netsim.py + POST /api/net-sim):
- pure builders for the observed phone write vocabulary (UICC_NAA.md §13):
  EPSNSC (A0 TLV with KSI/KASME/counts/algo, padded to the card's FCP record
  size; invalidate-wipe and invalidate-keep-key), LOCI/PSLOCI/EPSLOCI real
  and dummy forms (PLMN kept, LAC FFFE, status 01/02), Kc/KcGPRS (9-byte
  USIM and 33-byte GSM forms, 07 invalidates), EF.SMSstatus counter bump
  (read-modify-write), CBMI/CBMIR, the Location status event (9B 01 <st>,
  with the optional 13 07 location info for normal service) and the
  AUTHENTICATE APDU (TS 31.102 7.1.2.1) with DB/DC response parsing
- scenario runner executes the recipes under _CARD_LOCK, picks the first
  existing candidate path (ADF.USIM vs DF.GSM/DF.TELECOM), reads FCP/current
  records where the format is card-specific, skips the event unless the card
  subscribed to Location status, honours the scenario toggles and returns a
  per-step log; only D6/DC, ENVELOPE and AUTHENTICATE are ever sent
- GET /api/mcc-mnc serves the optional worldwide operator list
  (--mcc-mnc-list, default <workspace>/samples/mcc-mnc-list.json): ?q=
  search and ?random=1&exclude= for roaming; the list stays out of the repo

PWA:
- Phone pill gains a 'Network simulation' fieldset: one button per scenario
  (cold boot, EPS/2G attach, service lost, limited service, roaming denied,
  churn, SMS received, CB reconfig, AUTHENTICATE), a collapsed Parameters
  block (operator search + random roaming, LAC/Cell ID/TAC/RAC, optional
  identities, toggles, churn count/delay) and a step log with SWs
- i18n EN/RU, help/README/api.md/AGENTS.md updated; version 2.5.0,
  SW cache simple-v193

Tests: tests/test_netsim.py (19), frontend/tests/netsim.test.js (3) and
html guards - 423 frontend / 280 Python, all passing

frontend/tests/html.test.js

@@ -202,6 +202,21 @@ test('every help anchor used by the UI exists in help.html', () => {
     assert.ok(html.includes("? 'scp81-scripts' : 'scp81-listener'"));
 });
 
+test('phone simulator has the network-simulation fieldset', () => {
+    assert.ok(html.includes('data-l10n="Network simulation"'));
+    for (const s of ['cold_boot', 'attach_eps', 'attach_2g', 'service_lost',
+        'limited_service', 'roaming_denied', 'churn', 'sms_received',
+        'cb_reconfig', 'authenticate']) {
+        assert.ok(html.includes("netSimRun('" + s + "')"), s);
+    }
+    assert.ok(html.includes('id="netsim-op-search"'));
+    assert.ok(html.includes('id="netsim-log"'));
+    assert.ok(html.includes('id="netsim-status"'));
+    assert.match(html, /id="netsim-mcc" value="001"/);
+    // scenario buttons need the card (the server writes real EFs)
+    assert.match(html, /data-needs="card" onclick="netSimRun\('service_lost'\)"/);
+});
+
 test('SCP81 listener exposes its four modes with the matching notes', () => {
     for (const v of ['tls', 'redirect', 'passthru', 'dump']) {
         assert.ok(html.includes('value="' + v + '"'), v);

frontend/tests/netsim.test.js

@@ -0,0 +1,86 @@
+const { test } = require('node:test');
+const assert = require('node:assert');
+const fs = require('node:fs');
+const path = require('node:path');
+
+const html = fs.readFileSync(path.join(__dirname, '..', 'index.html'), 'utf8');
+
+function extractFunc(src, name) {
+	const re = new RegExp('function\\s+' + name + '\\s*\\([^)]*\\)\\s*\\{');
+	const m = re.exec(src);
+	if (!m) throw new Error('function ' + name + ' not found');
+	let i = m.index + m[0].length - 1;
+	let depth = 0;
+	for (; i < src.length; i++) {
+		if (src[i] === '{') depth++;
+		else if (src[i] === '}') {
+			depth--;
+			if (depth === 0) break;
+		}
+	}
+	return src.slice(m.index, i + 1);
+}
+
+let code = '';
+for (const f of ['netSimRandomHex', 'netSimDice', 'netSimVal', 'netSimChk', 'netSimParams', 'netSimStepText']) {
+	code += extractFunc(html, f) + '\n';
+}
+code += 'function t(k){return k;}\n';
+code += 'var _fields = {};\nvar document = { getElementById: function(id){ return _fields[id] || null; } };\n';
+eval(code);
+
+test('netSimRandomHex produces uppercase hex of the requested length', () => {
+	const h = netSimRandomHex(4);
+	assert.match(h, /^[0-9A-F]{8}$/);
+	assert.match(netSimRandomHex(1), /^[0-9A-F]{2}$/);
+});
+
+test('netSimParams maps form fields and checkboxes', () => {
+	_fields = {
+		'netsim-mcc': { value: '262' },
+		'netsim-mnc': { value: '01' },
+		'netsim-lac': { value: '  6CD7  ' },
+		'netsim-lac-empty': { value: '' },
+		'netsim-churn-count': { value: '5' },
+		'netsim-send-event': { checked: true },
+		'netsim-dummy-locations': { checked: false },
+		'netsim-invalidate-epsnsc': { checked: true },
+		'netsim-keep-kasme': { checked: true },
+		'netsim-write-kc': { checked: false },
+		'netsim-sms-location': { checked: true },
+		'netsim-cb-clear': { checked: false },
+	};
+	const p = netSimParams();
+	assert.strictEqual(p.mcc, '262');
+	assert.strictEqual(p.mnc, '01');
+	assert.strictEqual(p.lac, '6CD7');
+	assert.strictEqual(p.churn_count, '5');
+	assert.strictEqual(p.send_event, true);
+	assert.strictEqual(p.dummy_locations, false);
+	assert.strictEqual(p.invalidate_epsnsc, true);
+	assert.strictEqual(p.keep_kasme, true);
+	assert.strictEqual(p.write_kc, false);
+	assert.strictEqual(p.sms_location, true);
+	assert.strictEqual(p.cb_clear, false);
+	// unset fields are omitted so the server fills its own defaults
+	assert.ok(!('tmsi' in p));
+	assert.ok(!('kasme' in p));
+});
+
+test('netSimStepText renders the step log lines', () => {
+	assert.strictEqual(
+		netSimStepText({ action: 'update_binary', file: 'loci', path: 'ADF.USIM/6F7E', data: 'FF01', sw: '9000' }),
+		'update_binary loci (ADF.USIM/6F7E) FF01 → SW 9000');
+	assert.strictEqual(
+		netSimStepText({ action: 'update_record', file: 'epsnsc', path: 'ADF.USIM/6FE4', data: 'A0', sw: '9000' }),
+		'update_record epsnsc (ADF.USIM/6FE4) A0 → SW 9000');
+	assert.strictEqual(
+		netSimStepText({ action: 'event', file: 'location_status', data: '9B0102', sw: '9000' }),
+		'ENVELOPE location_status 9B0102 → SW 9000');
+	assert.strictEqual(
+		netSimStepText({ action: 'skip', file: 'location_status', note: 'event 0x03 not in SET UP EVENT LIST' }),
+		'skip location_status — event 0x03 not in SET UP EVENT LIST');
+	assert.match(
+		netSimStepText({ action: 'authenticate', parsed: { type: 'synchronisation_failure' }, sw: '9000', response: 'DC10AA' }),
+		/^AUTHENTICATE synchronisation_failure → SW 9000 DC10AA$/);
+});