Decouple non-UI CLI startup from config_ui

Stop aman.py from importing the GTK settings module at module load so version, init, bench, diagnostics, and top-level help can start without pulling in the UI stack.\n\nPromote PyGObject and python-xlib into main project dependencies, switch the documented source install surface to plain uv/pip commands, and teach the portable, deb, and Arch packaging flows to install filtered runtime requirements before the Aman wheel so they still rely on distro-provided GTK/X11 packages.\n\nAdd regression coverage for importing aman with config_ui blocked and for the portable bundle's new requirements payload, then rerun the focused CLI/diagnostics/portable tests plus py_compile.

scripts/package_common.sh

@@ -84,3 +84,30 @@ render_template() {
     sed -i "s|__${key}__|${value}|g" "${output_path}"
   done
 }
+
+write_runtime_requirements() {
+  local output_path="$1"
+  require_command python3
+  python3 - "${output_path}" <<'PY'
+from pathlib import Path
+import re
+import sys
+import tomllib
+
+output_path = Path(sys.argv[1])
+exclude = {"pygobject", "python-xlib"}
+project = tomllib.loads(Path("pyproject.toml").read_text(encoding="utf-8"))
+dependencies = project.get("project", {}).get("dependencies", [])
+filtered = []
+for dependency in dependencies:
+    match = re.match(r"\s*([A-Za-z0-9_.-]+)", dependency)
+    if not match:
+        continue
+    name = match.group(1).lower().replace("_", "-")
+    if name in exclude:
+        continue
+    filtered.append(dependency.strip())
+output_path.parent.mkdir(parents=True, exist_ok=True)
+output_path.write_text("\n".join(filtered) + "\n", encoding="utf-8")
+PY
+}