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/prompt/presets/minimal.json

@@ -0,0 +1,14 @@
+{
+  "name": "minimal",
+  "title": {"uk": "Мінімальне: каталог, git і ❯", "en": "Minimal: directory, git and ❯"},
+  "frame": "plain",
+  "open": "",
+  "close": "",
+  "sep": " ",
+  "segments": [
+    {"type": "cwd", "mode": "short", "fg": "blue", "bold": true},
+    {"type": "git", "fg": "magenta"},
+    {"type": "status", "fg": "red", "bold": true},
+    {"type": "symbol", "char": "❯", "fg": "green", "bold": true}
+  ]
+}