refactor: Harden template rendering against formatter interference

lib/scaffold.sh

@@ -16,6 +16,12 @@ render_template() {
   local content
   content=$(<"$template_file")
 
+  # HARDENING: collapse any “spaced” placeholders from a formatter
+  #   { { KEY } }  ->  {{KEY}}   (KEY = UPPERCASE/underscore)
+  # Defense in depth: if Prettier or a copy-paste breaks the syntax again,
+  # the scaffold fixes itself. sed is a core utility (like tr/date already used here).
+  content=$(sed -E 's/\{[[:space:]]*\{[[:space:]]*([A-Z_]+)[[:space:]]*\}[[:space:]]*\}/{{\1}}/g' <<<"$content")
+
   # Defaults (:-) so master-repo templates render even when GENOME_* are unset
   # (scaffold_master runs before any genome; set -u would otherwise abort here).
   local genome_name_upper