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/python/das_shell/cli.py

@@ -0,0 +1,49 @@
+"""Shared bits of the dprompt and dbanner command lines."""
+
+import os
+import sys
+
+from .i18n import t
+
+
+def die(prog, uk, en, code=1):
+    print(f"{prog}: {t(uk, en)}", file=sys.stderr)
+    sys.exit(code)
+
+
+def need_root(argv):
+    """Runs the command again through sudo with the same arguments."""
+    if os.geteuid() == 0:
+        return
+    script = os.path.abspath(sys.argv[0])
+    try:
+        os.execvp("sudo", ["sudo", sys.executable, script] + argv)
+    except OSError as e:
+        print(f"sudo: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+def resolve(spec):
+    """A file argument as an absolute path (sudo starts elsewhere); names stay names."""
+    if os.sep in spec or spec.endswith(".json"):
+        return os.path.abspath(spec)
+    return spec
+
+
+def run_tui(prog, loader):
+    try:
+        app = loader()
+    except ImportError as e:
+        die(prog, f"немає бібліотеки Textual ({e}); встановіть python3-textual",
+            f"the Textual library is missing ({e}); install python3-textual")
+    app.run()
+    return 0
+
+
+def write_file(path, text, mode=0o644):
+    os.makedirs(os.path.dirname(path), exist_ok=True)
+    tmp = path + ".tmp"
+    with open(tmp, "w", encoding="utf-8") as f:
+        f.write(text)
+    os.chmod(tmp, mode)
+    os.replace(tmp, path)