feat(anaconda): integrate anaconda installer with openbox and add licensing documentation

Add Anaconda installer integration to FWS live environment:

- Implement Anaconda launcher in .xinitrc with comprehensive error logging and debugging support
- Add anaconda and anaconda-widgets packages to baseline and releng ISO configs
- Fix anaconda-widgets PKGBUILD: replace gladeui with glib2-devel, disable Glade module
- Update anaconda PKGBUILD with improved dependencies and build configuration
- Add python-blivet PKGBUILD with detailed dependency documentation

Enhance documentation and branding:

- Expand AUTHORS.rst to clarify FWS vs archiso authorship and licensing
- Update CONTRIBUTING.rst with inbound=outbound licensing policy and DCO requirements
- Extend README.md with comprehensive legal basis table and licensing checklist
- Remove Arch Linux references from MOTD and update to FWS GitHub project page
- Fix fastfetch.sh to avoid read-only variable conflict in zsh
- Add xterm to packages for installer debugging

All changes maintain GPL-3.0-or-later compliance and improve GPL offer transparency.

configs/baseline/packages.x86_64

@@ -93,6 +93,8 @@ xorg-xrandr
 xorg-xsetroot
 openbox
 ttf-dejavu
+# Terminal X : debug de l'installateur + entrée « Terminals » du menu Openbox.
+xterm
 
 # --- Agents VM (pratique pour tester l'ISO) ---
 qemu-guest-agent
@@ -101,3 +103,8 @@ open-vm-tools
 
 # --- FWS (fws-local) ---
 winboat-bin
+
+# --- Installateur Anaconda (fws-local) ---
+# 'anaconda' tire automatiquement anaconda-widgets + toutes ses dépendances
+# (python-blivet, pykickstart, libreport, gtk3, NetworkManager…).
+anaconda