fix: SCP80/RAM re-read the preset before every operation; no counter bump on a rejected send (v3.6.3)

The SCP80/RAM forms hold a copy of the preset (counter, keys, TAR, SPI).
Editing the preset on the Cards tab saved correctly, but the form kept the
old copy: the operation sent the stale counter (the card answers cntr_low)
and the post-send sync wrote the stale value back over the preset - the
saved counter silently reverted.  Reproduced in a real DOM:

  after select in SCP80:  preset=0000000001  sp=0000000001
  after Cards edit+save:  preset=00000000AA  sp=0000000001
  after a sync:           preset=0000000001  (edit lost)

- `cardsApply()` split into `cardsApplyFields()` (field copy, no packet) and
  `cardsApply()` = fields + genSp; new `spRefreshFromPreset(selId)` re-reads
  the selected preset from `sp-card-sel` / `ram-card-sel` and re-applies it.
- `pysimSendOta()` and `ramExecute()` call it before starting, so every
  SCP80/RAM operation uses the preset as it is now.
- A rejected send no longer advances the counter: new `spPorAccepted(por)`
  gates the advance+write-back in `pysimSendOta`, the Explore pagination and
  its GET DATA step, and the server's RAM install (`_ram_next_cntr`: advance
  only for `por_ok`/`no_por` steps).  A failed install still returns
  `final_cntr` (the accepted prefix) and the PWA persists it, so a retry
  never replays a counter the card already consumed.
- tests: cards_counter.test.js (the stale-form regression, RAM selector,
  fields-without-genSp, spPorAccepted) and `_ram_next_cntr` cases; the
  cards_form/ram harnesses updated for the split.
- docs/api.md counter semantics; AGENTS preset-source-of-truth rule.

607 frontend / 488 Python green; version 3.6.3; sw simple-v276.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pysim-simple-server"
-version = "3.6.2"
+version = "3.6.3"
 description = "HTTP REST server wrapping pysim for the SIMple PWA"
 requires-python = ">=3.8"
 # pysim is a git-only dependency installed explicitly by setup.bat/setup.sh.