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/art/trident-small.json

@@ -0,0 +1,40 @@
+{
+  "name": "trident-small",
+  "title": {
+    "uk": "Тризуб, малий",
+    "en": "Tryzub, small"
+  },
+  "styles": {
+    "a": {
+      "fg": "bright_yellow",
+      "bg": null,
+      "bold": false
+    }
+  },
+  "lines": [
+    "",
+    "  ▄    ██    ▄",
+    "  █▀▄  ██  ▄▀█",
+    "  █ █  ██  █ █",
+    "  █  ▄ ██ ▄  █",
+    "  █▄▄▀ ██ ▀▄▄█",
+    "  █▀█▄█  █▄█▀█",
+    "  █▄ ██████ ▄█",
+    "   ▀▀▀████▀▀▀",
+    "      ▀██▀",
+    ""
+  ],
+  "style_map": [
+    "",
+    "  a    aa    a",
+    "  aaa  aa  aaa",
+    "  a a  aa  a a",
+    "  a  a aa a  a",
+    "  aaaa aa aaaa",
+    "  aaaaa  aaaaa",
+    "  aa aaaaaa aa",
+    "   aaaaaaaaaa",
+    "      aaaa",
+    ""
+  ]
+}