Fix three regressions introduced by the previous simplification

Fix three regressions introduced by the previous simplification

1. URL normalization: "/${VAR##//}" strips the leading slash when the
   input already starts with "/". Fix: strip trailing and leading slash
   separately, then prepend "/": VAR="${2%%/}"; VAR="/${VAR##/}".
   Affects --current, --archived, and --canonical in both scripts.
   Consequences: missing leading "/" in frontmatter url/canonical fields
   (Hugo+Astro) and in the static-copy destination path (Hugo).

2. Root page title (Hugo+Astro): TITLE_YAML was unified to use
   $PAGE | jq '.name' for all pages. For index.html the Maven project
   name must come from $JSON | jq '.project', not from the site.xml
   page name. Moved TITLE_YAML assignment into the if/else branches.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>