feat: TAR probe + the SPI1 counter-tracking rule; keyless packets build again (v3.8.0)

Three things learned from probing a live card, plus the capability they enabled:

1. Counter tracking follows SPI1.b5b4 (TS 102 225 5.1.1): with 00 the counter
   is "present, ignored, never updated", so a packet without a counter check
   must leave every counter untouched.  _counter_tracked() now guards
   /api/send-ota (no final_cntr, no persistence, a log line), the RAM step
   sender and the test runner; _preset_counter_persist() requires a non-zero
   key version (the "single keyset" fallback could advance a keyset spuriously
   for a keyless send).  The PWA advances the form counter only when the server
   reports final_cntr and says "counter not tracked" otherwise.

2. The spec's no-security form builds again: _ota_keyset() refused the valid
   KIc/KID '00' (TS 102 225 A.2: '00' is legal with SPI1.b3=0 for KIc and
   SPI1.b2b1=00 for KID) because pySim wants an algorithm.  An unknown nibble
   is now refused only when the algorithm is actually used (ciphering / a
   ciphered PoR for KIc, RC/CC/DS / a MAC'd PoR for KID) and 'implicit' codes
   the nibble as 0 otherwise - POST /api/send-ota {apdu, spi1:"00", kic:"00",
   kid:"00"} now builds 0D00010000B0000000000000010000A40000, the exact packet
   the card accepted (a fake 15/15 was refused with 6200).  A no-security PoR
   is decodable again too, and a requested-but-missing PoR sets por_missing
   on the plain path as well.

3. TAR probe (POST /api/tar-probe, RAM op "Probe TARs"): one secured packet per
   TAR - the standard allocations of TS 101 220 V18.3.0 Annex D, Table D.1
   (TAR_PROBE_TARS), or a custom list - carrying a harmless C-APDU (SELECT MF)
   with the preset's keyset and SPI 16/01.  Each TAR is classified
   (registered / no_answer / no_por / refused) from the ENVELOPE verdict and
   the application's PoR, counters advance and persist normally, and the run is
   refused when SPI1 has no counter check.  Live on a card: 000000, B00000 and
   B00001 registered (compact-format applications, answering 6D00 / 6B00),
   the expanded-format TARs, USAT, multiplexing and CASD refused with 6200 -
   with the keyless form the same card accepted every TAR and answered no PoR.

Docs (api.md, help EN/RU, AGENTS), sw cache simple-v337.  Tests: 618 Python
(no-security build, the algorithm-only-when-used rule, the tracking rule, the
persist guard, the probe classification) and 736 Node (the probe renderer and
wiring, spCounterTracked).

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'simple-v336';
+const CACHE = 'simple-v337';
 const URLS = [
   'index.html',
   'help.html',