fix(spacing): connect section spacing to design token system

Wire .hbb-section to var(--hb-spacing-section) instead of hardcoded 6rem,
enabling hugoblox.layout.spacing (compact/comfortable/spacious) to take effect.

- Default to "spacious" (6rem) to preserve existing visual layouts
- Per-section override via design.spacing.padding still works (inline > class)
- Remove dead design.spacing frontmatter field from all templates
- Set correct layout.spacing token in each template's params.yaml

Closes #3314

modules/blox/assets/css/framework/components.css

@@ -2,8 +2,8 @@
 @layer components {
   /* Section styles for Hugo Blox blocks */
   .hbb-section {
-    padding-top: 6rem;
-    padding-bottom: 6rem;
+    padding-top: var(--hb-spacing-section, 6rem);
+    padding-bottom: var(--hb-spacing-section, 6rem);
   }
 
   .section-subheading {

modules/blox/layouts/_partials/functions/get_theme_config.html

@@ -148,7 +148,7 @@
 {{ $hb_layout := $hb.layout | default dict }}
 {{ $layout := dict 
     "radius" ($hb_layout.radius | default "md")
-    "spacing" ($hb_layout.spacing | default "comfortable")
+    "spacing" ($hb_layout.spacing | default "spacious")
 }}
 
 {{/* Return theme config dict */}}

modules/blox/layouts/_partials/functions/layout_tokens.html

@@ -28,9 +28,9 @@
 {{ end }}
 
 {{/* Map spacing tokens to CSS values */}}
-{{ $spacing := .layout.spacing | default "comfortable" }}
-{{ $spacing_base := "1rem" }}
-{{ $spacing_section := "4rem" }}
+{{ $spacing := .layout.spacing | default "spacious" }}
+{{ $spacing_base := "1.25rem" }}
+{{ $spacing_section := "6rem" }}
 {{ if eq $spacing "compact" }}
   {{ $spacing_base = "0.75rem" }}
   {{ $spacing_section = "2.5rem" }}
@@ -41,7 +41,7 @@
   {{ $spacing_base = "1.25rem" }}
   {{ $spacing_section = "6rem" }}
 {{ else }}
-  {{ warnf "LAYOUT TOKEN WARNING: Unknown spacing value '%s'. Expected: compact | comfortable | spacious. Falling back to 'comfortable'." $spacing }}
+  {{ warnf "LAYOUT TOKEN WARNING: Unknown spacing value '%s'. Expected: compact | comfortable | spacious. Falling back to 'spacious'." $spacing }}
 {{ end }}
 
 <style>