feat(cli/build/defaults): ensure deterministic alphabetical sorting for applications and users

- Added sorting by application key and user key before YAML output.
- Ensures stable and reproducible file generation across runs.
- Added comprehensive unit tests verifying key order and output stability.

See: https://chatgpt.com/share/68ef4778-a848-800f-a50b-a46a3b878797

cli/build/defaults/applications.py

@@ -83,6 +83,13 @@ class DefaultsGenerator:
             print(f"Error during rendering: {e}", file=sys.stderr)
             sys.exit(1)
 
+        # Sort applications by application key for stable output
+        apps = result.get("defaults_applications", {})
+        if isinstance(apps, dict) and apps:
+            result["defaults_applications"] = {
+                k: apps[k] for k in sorted(apps.keys())
+            }
+
         # Write output
         self.output_file.parent.mkdir(parents=True, exist_ok=True)
         with self.output_file.open("w", encoding="utf-8") as f:

cli/build/defaults/users.py

@@ -220,6 +220,10 @@ def main():
         print(f"Error building user entries: {e}", file=sys.stderr)
         sys.exit(1)
 
+    # Sort users by key for deterministic output
+    if isinstance(users, dict) and users:
+        users = OrderedDict(sorted(users.items()))
+
     # Convert OrderedDict into plain dict for YAML
     default_users = {'default_users': users}
     plain_data = dictify(default_users)