deliverables/gartner: harden fonts; drop dead duplicate deck

Some viewers saw garbled text in the Gartner deck. Root cause: each @font-face
listed local('Garnett'…)/local('Apercu Mono Pro'…) BEFORE the embedded woff2,
so a broken/mismatched local font on a viewer's machine could override the good
bundled font (the var fallbacks don't catch this — a bad local match still
"succeeds").

- Drop local() from all three @font-face so the bundled woff2 is always used.
  Garnett / Apercu Mono Pro are proprietary brand fonts (not on public CDNs);
  inline woff2 is the most reliable delivery. Generic fallbacks
  (…,Arial,sans-serif / …,monospace) remain as the last-resort safety net.
- Delete the stale top-level deliverables/gartner-product-analytics-demo.html
  duplicate; the live deck is deliverables/gartner/product-analytics-demo.html.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ak--47