feat(baseline): add locale generation and rootfs mounting infrastructure

Add locale configuration, systemd service for rootfs mounting, and customization script:

- Add locale.gen to generate en_US.UTF-8 locale required by Anaconda
- Add fws-rootfsbase.service to expose squashfs as /run/rootfsbase for Anaconda LiveOS payload detection
- Add customize_airootfs.sh to run locale-gen during image build
- Add python-iso639 0.1.4 PKGBUILD (local package with correct find() API)
- Add python-langtable 0.0.71 PKGBUILD (local package with list_common_languages())
- Remove python-iso639 and python-langtable from AUR packages due to version/API incompatibilities
- Update LOCAL_BUILD_ORDER to include new local packages

pkgbuilds/python-langtable/PKGBUILD

@@ -0,0 +1,36 @@
+# Maintainer: FWS
+# ============================================================================
+#  python-langtable — tables de langues/locales/claviers (dépendance Anaconda).
+#
+#  ⚠️  L'AUR python-langtable est figé à 0.0.51, TROP VIEUX pour Anaconda 45.8 :
+#      le spoke d'accueil GUI fait localization.get_common_languages() →
+#      langtable.list_common_languages(), fonction ajoutée seulement en
+#      langtable 0.0.71 (« derived from gnome-control-center »). Avec 0.0.51 :
+#      « AttributeError: module 'langtable' has no attribute
+#      'list_common_languages' » → le GUI plante au démarrage.
+#
+#      On package donc 0.0.71 en LOCAL (même nom → satisfait la dép anaconda) et
+#      on RETIRE python-langtable de setup-aur.sh AUR_PACKAGES.
+# ============================================================================
+pkgname=python-langtable
+_pyname=langtable
+pkgver=0.0.71
+pkgrel=1
+pkgdesc="Guessing reasonable defaults for locale/keyboard/territory/language (dépendance Anaconda)"
+arch=('any')
+url="https://github.com/mike-fabian/langtable"
+license=('GPL-3.0-or-later' 'MIT')
+depends=('python' 'python-setuptools' 'gzip')
+makedepends=('python-build' 'python-installer' 'python-wheel' 'python-setuptools')
+source=("$pkgname-$pkgver.tar.gz::https://files.pythonhosted.org/packages/source/l/langtable/langtable-$pkgver.tar.gz")
+sha256sums=('f9d39c06d5182ea14eb4576bf1da8875af1d44efb166e55d6865b3b59b8ac617')
+
+build() {
+  cd "$srcdir/langtable-$pkgver"
+  python -m build --wheel --no-isolation
+}
+
+package() {
+  cd "$srcdir/langtable-$pkgver"
+  python -m installer --destdir="$pkgdir" dist/*.whl
+}