fix: update paths for trips/japan-korea-2026/dailies restructure

- Update post form parent, Makefile demo targets, and test scripts to use
  new trip-scoped paths (01.trips/japan-korea-2026/01.dailies)
- Rename tracker.spec.js → dailies.spec.js and update all /tracker URLs
  to /trips/japan-korea-2026/dailies across nav.spec.js, post.spec.js,
  helpers.js, and dailies.spec.js
- Add Italy 2025 demo trip to Makefile demo-load/demo-reset targets

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

scripts/test-form-config.sh

@@ -26,7 +26,7 @@ grep -q "add_page:\|addpage:" "$FORM" && ok "Process action is 'add_page' (plugi
 
 # Config must be in frontmatter, not in the process block
 check_grep "pageconfig block exists in frontmatter"       "^pageconfig:"
-check_grep "parent set to /tracker"                       "parent: '/tracker'"
+check_grep "parent set to /trips/japan-korea-2026/dailies" "parent: '/trips/japan-korea-2026/dailies'"
 check_grep "slug_field set (determines entry folder name)" "slug_field:"
 check_grep "pagefrontmatter block exists in frontmatter"  "^pagefrontmatter:"
 check_grep "template: entry (creates entry.md filename)"  "template: entry"