README: add architecture diagrams (EN/RU)

Both READMEs gain a capture-and-analysis diagram right under the screenshot:
simtrace2-pysniff and sigrok_iso7816_stream feed the GSMTAP UDP :4729
listener, SIMtrace2 hardware can be read directly over USB, PCAP/COMPRION
traces come from files, and simtrace-analyser-server decodes/stores into
SQLite and serves the web UI.  The SVGs carry title/desc and role=img, use
only inline presentation attributes (no scripts, no external refs) and render
without clipped text; the RU text matches the EN layout.

The runtime zip includes both diagrams so the embedded READMEs keep working,
and a new drift guard checks that every image a README references is present
in the archive.  RU wording: "устанавливаемое PWA" (neuter agreement).

558 Python + 80 Node tests.

scripts/build_release_zip.py

@@ -40,6 +40,8 @@ ROOT_FILES = (
     'README.md',
     'README_RUS.md',
     'frontend.png',
+    'architecture_en.svg',
+    'architecture_ru.svg',
     'LICENSE',
 )