v1.0.6 shipped: curated stamps + analytics

We shipped v1.0.6 with a focused release package: new curated stamp assets, analytics instrumentation, and production cleanup.

Design updates: Zürich and Lötschental now use curated vintage-style stamp artwork, aligned with the current Swiss poster direction and integrated into the live stamp rendering flow.

Product instrumentation: Vercel Analytics is now mounted at app root, so we can track real usage patterns and prioritize changes with data instead of guesswork.

Technical cleanup: obsolete stamp prompt artifact files were removed as part of the release pass, keeping the pipeline easier to maintain.

This release shipped to main with auto-deploy on Vercel. OJP bearer-token auth was shipped in parallel and is covered in a separate dedicated post.