feat(structures): add group and sidecar support for LLM integration

data/structures/bundle.yml

@@ -1,5 +1,6 @@
 comment: >-
   Bundles a selection of files into a single file.
+group: partial
 arguments:
   page:
   match:

data/structures/dependency.yml

@@ -3,6 +3,7 @@ comment: >-
   the requirement as semantic version string, e.g. `0.141.0`. The function
   returns true if Hugo's major version is equal and the minor.patch version is
   equal or greater than the provided version string. Any labels are ignored.
+group: partial
 arguments:
   version:
     type: string

data/structures/description.yml

@@ -1,4 +1,5 @@
 comment: Retrieves the (meta) description of a page.
+group: partial
 arguments:
   page:
     type:

data/structures/get-contact.yml

@@ -1,5 +1,6 @@
 comment: >-
   Retrieves contact details by name from a data asset.
+group: partial
 arguments:
   contact:
     type: string

data/structures/log.yml

@@ -1,4 +1,5 @@
 comment: Logs a rich warning or error to the terminal.
+group: partial
 arguments:
   type:
     type: select

data/structures/urljoin.yml

@@ -2,6 +2,7 @@ comment: >-
   Joins the provided elements into a URL string. This partial uses urls.JoinPath
   introduced by Hugo v0.112.0 when available. Only use this partial when
   depending on an older version of Hugo.
+group: partial
 arguments:
   base:
     type: string

layouts/_partials/utilities/InitTypes.html

@@ -102,6 +102,19 @@
     {{ else }}
         {{ $args = index (index (index site.Data.structures.components $bookshop) (printf "%s.bookshop" $bookshop)) "blueprint" | default dict }}
         {{ $args = merge $args (dict "_bookshop_name" nil "_ordinal" nil "id" nil) }}
+        {{/* Load augmented sidecar (e.g. preview.yml) if present */}}
+        {{ $sidecarData := index (index site.Data.structures.components $bookshop) $bookshop | default dict }}
+        {{ range $key, $sidecarArgDef := ($sidecarData.arguments | default dict) }}
+            {{ if reflect.IsMap $sidecarArgDef }}
+                {{/* Convert kebab sidecar key to snake_case to match blueprint key format */}}
+                {{ $snakeKey := replaceRE "-" "_" $key }}
+                {{ $existing := index $args $snakeKey | default (index $args $key) | default dict }}
+                {{ if not (reflect.IsMap $existing) }}{{ $existing = dict }}{{ end }}
+                {{/* Prefer snake key if it exists in blueprint, otherwise use as-is */}}
+                {{ $targetKey := cond (isset $args $snakeKey) $snakeKey $key }}
+                {{ $args = merge $args (dict $targetKey (merge $existing $sidecarArgDef)) }}
+            {{ end }}
+        {{ end }}
     {{ end }}
 
     {{/* Merge any child arguments */}}