v3.22.0: the event action uses the Simulator's forms (all modelled events)

The test-script event action edited its fields as a JSON textarea and only
accepted the four events events.py builds; every other event needed the raw
envelope action with hand-copied hex.  It now renders the same EVENT_FORMS
form the Phone tab's send dialog uses, for every modelled event (29; no
release gating - a script may target another card).

- PWA: the field renderer/collector is shared (eventFormFieldsHtml /
  eventFormValues / eventFormPatternError / eventFormSrc / eventFieldGroupsUpdate);
  the Phone tab keeps its ids, its release gating and its onchange updaters,
  the step editor uses test-f-ev- ids, the generic group updater and a live
  Event data (hex) preview with the one-ENVELOPE check.  The event select
  lists all EVENT_FORMS events (the numeric keys are decimal strings -
  parseInt(k, 10)); the action stores the collected fields, the built data
  and the event's source (fixed cfg.src or the cfg.srcField input - the
  action never carried src before, so MT call / IMS registration / slices
  could not be network-sourced).  The JSON textarea is gone.
- engine: the `event` action keeps `fields` validation for the four
  server-built events (a stray data hex is ignored) and accepts the
  form-built `data` for every other event - hex-validated and checked
  against events.EVENT_DATA_MAX (244, the one-ENVELOPE budget; server.py's
  _EVENT_DATA_MAX now reads it from events.py).  The runner builds the four
  at run time (fresh host clock) and sends the stored data for the rest.
- tests: the engine's data path (accepted / missing / malformed / oversized,
  the four still fields-built), the runner sending the data (fake scc), the
  editor's collect/prefill/patterns/source (Node), the shared helpers.
  Docs: test-scripts.md, api.md, help EN/RU.  Tests: 838 frontend +
  797 Python; sw cache simple-v401.

docs/api.md

@@ -720,8 +720,10 @@ callers.
 
 **Action steps** (`type: "action"`): `kind` is `envelope` (`event`, `data`,
 optional `src` - the device-identities source override),
-`event` (`event` name or hex + `fields`, optional `src` - the semantic event
-download for 0x03/0x0B/0x12/0x1D), `menu-select` (`item_id` 1-255, or `text` +
+`event` (`event` name or hex + `fields` for the four server-built events
+0x03/0x0B/0x12/0x1D, or the PWA form's built `data` hex for any other event -
+validated as hex and against the one-ENVELOPE budget at load; optional `src`,
+the device-identities override), `menu-select` (`item_id` 1-255, or `text` +
 `mode` `exact`/`contains` (case-insensitive by default; `case_sensitive: true`
 forces an exact-case match) - the text is resolved against the card's cached
 SET UP MENU, which is refreshed whenever the card sends the menu), `file-write`