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-post.sh

@@ -7,7 +7,7 @@ set -euo pipefail
 BASE_URL="${GRAV_BASE_URL:-http://localhost:8081}"
 USER="${GRAV_TEST_USER:-}"
 PASS="${GRAV_TEST_PASS:-}"
-TRACKER="user/pages/01.tracker"
+TRACKER="user/pages/01.trips/japan-korea-2026/01.dailies"
 COOKIE_JAR="$(mktemp /tmp/grav-test-cookies.XXXXXX)"
 PASS_COUNT=0
 FAIL_COUNT=0