Rewrite landing to El component architecture

Full El component split: nav, hero, pillars, inference, pricing, footer, about,
enterprise, mission, viral, local_first, comparison, efficiency, environmental.

- About page rewritten first-person (Will's voice), photo included, no product spoilers
- Stripe checkout wired: env() reads STRIPE_SECRET_KEY/PRICE_* at startup
- Minor parent-onboarding callout added to pricing section
- Inference pricing: "at cost" removed, now "priced below competitors"
- Nav: wordmark image, About link active on /about
- .gitignore: excludes .env, dist/, generated HTML

.gitignore

@@ -0,0 +1,9 @@
+.env
+dist/
+.el/
+src/*.elc
+src/*.map.json
+src/index.html
+src/about.html
+src/terms.html
+src/enterprise-terms.html