refactor: archive GUI clients; keep minimal TUI with hooks/API

Move Qt/Tauri/full Web SPA under archive/, ship hermit as CLI/TUI plus
libcstcore and cst-webui/1 HTTP+SSE (turn lifecycle hooks, capabilities).

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/build_apk_android.sh

@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
-# Build the Qt Quick Android APK of app/ (the engine is linked in-process, so
+# ARCHIVED: Qt APK front end under archive/qt-app; not part of default Hermit builds.
+# Build the Qt Quick Android APK of archive/qt-app/ (the engine is linked in-process, so
 # the APK opens no port). This is the front end counterpart of
 # scripts/build_android.sh, which cross-builds the engine alone.
 #
@@ -150,7 +151,7 @@ cmake --build "$BUILD" --target apk -j"$JOBS"
 
 # AGP names the file after the variant and signing state
 # (android-build-release.apk vs ...-unsigned.apk), so take the newest one.
-APK="$(find "$BUILD/app/android-build/build/outputs/apk" "$BUILD" -name '*.apk' \
+APK="$(find "$BUILD/archive/qt-app/android-build/build/outputs/apk" "$BUILD" -name '*.apk' \
   -printf '%T@ %p\n' 2>/dev/null | sort -rn | head -1 | cut -d' ' -f2-)"
 [[ -n "$APK" && -f "$APK" ]] || { echo "no APK produced" >&2; exit 1; }
 echo