layouts: generate Netlify redirects from page aliases frontmatter

Update layouts/index.redirects to iterate all site pages and emit
server-side Netlify redirect lines for each alias declared in page
frontmatter. This allows content authors and localization teams to
manage redirects directly via the aliases field without editing the
central static/_redirects.base file.

Implementation details:
- Collects all RegularPages permalinks for conflict detection
- Resolves relative aliases using path.Dir of the page's RelPermalink
- Emits a warnf and skips any alias conflicting with a real page URL
- Localized aliases are fully supported; they appear in production
  builds where all language segments are rendered

Author: smeetagrawal23-sys

layouts/index.redirects

@@ -10,8 +10,30 @@
 # Dynamic latest API redirect - automatically points to current latest version
 /docs/reference/generated/kubernetes-api/latest/     /docs/reference/generated/kubernetes-api/{{ $latest }}/ 307
 /docs/reference/generated/kubernetes-api/latest/*   /docs/reference/generated/kubernetes-api/{{ $latest }}/:splat 307
+{{- end }}
+
+# Redirects generated from page aliases frontmatter
+{{ $allPagePermalinks := slice -}}
+{{- range .Site.RegularPages -}}
+  {{- $allPagePermalinks = $allPagePermalinks | append .RelPermalink -}}
 {{- end -}}
+{{- range .Site.Pages -}}
+  {{- $page := . -}}
+  {{- range $page.Aliases -}}
+    {{- $alias := . -}}
+    {{- if not (hasPrefix $alias "/") -}}
+      {{- $parentDir := path.Dir (strings.TrimSuffix "/" $page.RelPermalink) -}}
+      {{- $alias = printf "%s/%s/" $parentDir (strings.TrimSuffix "/" $alias) -}}
+    {{- end -}}
+    {{- /* Guard: warn if alias conflicts with a real page */ -}}
+    {{- if in $allPagePermalinks $alias -}}
+      {{- warnf "alias %q on page %q conflicts with an existing page permalink — skipping" $alias $page.RelPermalink -}}
+    {{- else }}
+{{ $alias }}    {{ $page.RelPermalink }}    301
+    {{- end -}}
+  {{- end -}}
+{{- end }}
 
 # Include all existing static redirects
-{{- $staticRedirects := readFile "static/_redirects.base" -}}
-{{ $staticRedirects }}
+{{ $staticRedirects := readFile "static/_redirects.base" -}}
+{{- $staticRedirects }}