feat: offline file list + SELECT picker for the SIM/USIM RFM builders (v3.4.0)

The SELECT rows (compact RFM chains and the Expanded Script C-APDU picker,
which shares the row editor) now have a file picker instead of typing FIDs,
paths or chains by hand.

Data:
- `pysim_simple_server/uicc_files.py` builds the standard file list cardless
  from pySim's profiles and application classes (CardProfileUICC + CardProfileSIM
  for the MF tree, every concrete CardApplication subclass for the ADFs) and
  writes `frontend/uicc_files.json` (490 entries: canonical FID path, symbolic
  name, fid, kind, root, ADF AID).  `tests/test_uicc_files.py` regenerates it
  and fails when pySim adds or renames files.  The asset is precached by the
  service worker, so the builders keep working offline.

Picker:
- Sources merged per canonical path: the loaded file-manager tree (card names
  and probed presence; probed-absent files hidden), custom files, and the
  shipped standard list (specs-default until "Probe all files" has run).
- Default list shows what the current method can express; "all files" reveals
  the rest, and picking one auto-switches the method - preferring path (one
  SELECT) over chain - with a note line explaining the switch.  A "starts in"
  selector sets the implicit current DF (UICC shared-FS RFM app starts in MF,
  an ADF RFM app in its ADF, TS 102 226 7.2/7.3 - the TAR decides; default per
  builder, overridable per row).
- Fill rules: by FID only for direct children of the current DF; path = FID
  sequence from MF without the MF identifier (ISO 7816-4) or the relative tail
  (USIM P1=09); chain stays relative and follows the TS 102 221 11.1.1.2 FID
  search order (children, parent, siblings), so no hop to the common ancestor.
  ADF roots are not pickable (selection is by AID; TS 102 226 7.1 forbids
  P1=04 for RFM) - the By AID method stays manual.

Tests/docs: frontend/tests/uicc_files.test.js (asset shape, merge/priority/
exclusion, fill matrix, relative chains, session-context tracking, option
grouping); help 2.1/2.2 EN+RU, READMEs, AGENTS.  sw cache -> simple-v242.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pysim-simple-server"
-version = "3.3.0"
+version = "3.4.0"
 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.