Terminal: Das prompt, dprompt and dbanner (0.9.1)

- das-shell 0.1.0: the Das two-line bash prompt by default (replaces the
  PS1 of Void's skel .bashrc once), dprompt (Textual prompt builder with
  presets and live preview) and dbanner (SSH login banner editor: canvas
  tools, fields with values, widgets, das-banner service for cached ones,
  Das OS logo and tryzub pictures). Python tests in make test.
- das-server 0.3.0 depends on das-shell; the server installer mentions
  dprompt and dbanner; the desktop image includes it.
- run-qemu.sh forwards the guest's SSH to localhost:2222.
- Hardware fixes: Ventoy menu icon, boot menu titles "Das OS <version>".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

srcpkgs/das-shell/files/share/banner/widgets/lib.sh

@@ -0,0 +1,14 @@
+# Shared by the dbanner widget scripts: colors and the user's language.
+# shellcheck shell=bash
+# shellcheck disable=SC2034
+Off=$'\e[0m' Bold=$'\e[1;37m' Red=$'\e[1;31m' Green=$'\e[1;32m' Yellow=$'\e[1;33m' Cyan=$'\e[1;36m' Gray=$'\e[0;90m'
+
+# say UKRAINIAN ENGLISH
+say() {
+	if [[ ${DBANNER_LANG:-} == uk ]]; then echo "$1"; else echo "$2"; fi
+}
+
+# level VALUE WARN CRIT: green below WARN, yellow below CRIT, red otherwise
+level() {
+	if (($1 < $2)); then echo -n "$Green"; elif (($1 < $3)); then echo -n "$Yellow"; else echo -n "$Red"; fi
+}