v3.15.0: test-script fixes for applet testing - preset id, kvn, PoR and file-list checks

Three gaps blocked SCP80 applet testing from the PWA:

- testRunPreset() still marshalled the pre-v3.8 flat preset fields
  (kic/kid/keys/counter/tar/spi1/spi2, all empty on a stored preset), so
  every SCP80 run failed with "SCP80 preset is incomplete: no keyset is
  defined".  The PWA sends the matched preset's id now and the server
  resolves it from the store (_test_run_preset_from_body; the inline
  `preset` body stays for API callers), so a run always uses the stored
  keysets, TARs and counters.  Regression tests on both sides.
- testscript._normalise_params dropped the scp80 step's `kvn` (the editor
  exposed it and the runner and validation consumed it, so scripts
  silently used the preset's first keyset).  kvn is validated (1-15) and
  passed through; the client-side problem check bounds it too.
- The PoR delivered as a SEND SHORT MESSAGE (PoR-in-submit, SPI2 bit 0x20)
  is decoded for the expect step that fetches it: the new `por` content
  check asserts the response status / R-APDU SW / response data, decoded
  with the preceding scp80 step's context (concatenated SMS accumulate
  across expectations).  The inline transport stays on the action
  (check.por / check.data).
- The new `files` content check asserts the File List of a REFRESH
  (TS 102 223 8.18, tag 12/92) - e.g. qualifier 00 = NAA initialization
  with full file change notification - as an order-insensitive set of FID
  paths.

The step editor exposes both checks; help EN/RU, docs/api.md and the new
authoring reference docs/test-scripts.md document the format.  Tests: 803
frontend + 680 Python; sw cache simple-v378.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pysim-simple-server"
-version = "3.14.2"
+version = "3.15.0"
 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.