feat(hugo): replace deprecated APIs for Hugo v0.156+ compatibility

Migrate site.Data → hugo.Data (42 occurrences), site.IsMultiLingual →
hugo.IsMultilingual, and site.AllPages → hugo.Sites nested range.
Simplify Netlify redirects template to use pre-processed aliases
instead of relLangURL per gohugoio/hugo#14408.

modules/blox/layouts/baseof.html

@@ -2,7 +2,7 @@
 {{ "<!-- This site was created with Hugo Blox. https://hugoblox.com -->" | safeHTML }}
 {{ printf "<!-- Last Published: %s -->" (now | time.Format ":date_long") | safeHTML }}
 {{- $language_code := site.LanguageCode | default "en-us" -}}
-<html lang="{{$language_code}}" {{ if in site.Data.i18n.rtl.rtl $language_code }}dir="rtl"{{else}}dir="ltr"{{end}}
+<html lang="{{$language_code}}" {{ if in hugo.Data.i18n.rtl.rtl $language_code }}dir="rtl"{{else}}dir="ltr"{{end}}
       data-wc-theme-default="{{ (lower site.Params.hugoblox.theme.mode) | default "system" }}"
       data-hbb-relurl="{{ "" | relURL }}">
   {{ partial "site_head" . }}