Add recipe generator and dish flattener

- create generate_recipe.py for universal template recipe generation
- support cartesian product expansion from recipes_manifest.yaml
- generate 72 unique recipes with proper filename disambiguation
- update Makefile with simplified validation using ksflatten
- keep ksflatten-relative script as-is for dish flattening

The generator reads recipe_templates.yaml and recipes_manifest.yaml to
produce recipe files that ksflatten then flattens into final dishes.

cook/recipe_templates.yaml

@@ -13,8 +13,7 @@ required:
   bootloader:
     "grub": bootloader/grub.ks
   storage:
-    "standard": storage/standard.ks
-    "encrypted": storage/encrypted.ks
+    "ext4": storage/standard.ks
   locale:
     "fr_CH": core/locale.ks 
   services:
@@ -34,6 +33,8 @@ required:
 modifiers:
   repository: 
     "rawhide": repo/rawhide-mirrors.ks
+  storage:
+    "encrypted": storage/encrypted.ks
   security:
     "disabled": core/security/disabled.ks
   initial-setup: