fix: make the Explore Delete buttons send the GP DELETE APDU (v3.6.6)

ramDeleteFromExplorer() called an undefined `_ber_len()` helper, so clicking
Delete / Delete All raised a ReferenceError right after the confirm and no
APDU was ever sent.  The inline builder also omitted the mandatory Le byte.

- new pure `ramDeleteApdu(aid, withCascade)` = GP Card Spec v2.3.1 Table
  11-20/23 form: `80 E4 00 <p2> <Lc> 4F <len> <AID> 00` (P2 00 = object,
  80 = object and related objects), used by the Explore handler.
- `scp81DeleteApdus()` (the "Delete AID" script template) now shares the
  same builder: it used to send the raw AID without the mandatory '4F' TLV.
- tests: exact bytes for 7/16-byte AIDs and both P2 modes, the SCP81 script
  expectations updated to the TLV form, and a wiring check that the undefined
  helper call does not come back (`_ber_len(`).

611 frontend / 495 Python green; version 3.6.6; sw simple-v279.

frontend/tests/scripts.test.js

@@ -26,6 +26,8 @@ function extractFunc(src, name) {
 global.t = (s) => s;
 eval(extractFunc(html, 'cardsPskMap'));
 eval(extractFunc(html, 'scriptsParseApdus'));
+eval(extractFunc(html, 'berLenStr'));
+eval(extractFunc(html, 'ramDeleteApdu'));
 eval(extractFunc(html, 'scp81DeleteApdus'));
 eval(extractFunc(html, 'scp81LogLine'));
 eval(extractFunc(html, 'scp81LogEntryHtml'));
@@ -82,9 +84,9 @@ test('scriptsParseApdus accepts comments and whitespace, rejects bad lines', ()
 
 test('scp81DeleteApdus builds GP DELETE APDUs per AID', () => {
 	assert.deepStrictEqual(scp81DeleteApdus(['A000000003000000'], '00'),
-		['80E4000008A00000000300000000']);
+		['80E400000A4F08A00000000300000000']);
 	assert.deepStrictEqual(scp81DeleteApdus(['A000000003000000', 'A000000100'], '80'),
-		['80E4800008A00000000300000000', '80E4800005A00000010000']);
+		['80E400800A4F08A00000000300000000', '80E40080074F05A00000010000']);
 	assert.deepStrictEqual(scp81DeleteApdus([], '00'), []);
 });