refactor: rename nutriphi module to food (Essen)

Complete rename across the entire monorepo pre-launch:
- Module, routes, API, i18n, standalone landing app directories
- All code identifiers, display names, logo component
- German user-facing label: "Essen" (English brand stays "Food")
- Dexie table nutriFavorites -> foodFavorites
- Infra configs (docker-compose, cloudflared, nginx, wrangler)

Zero residue of nutriphi remains. No data migration needed (pre-launch).

Follow-up: run pnpm install, update Cloudflare DNS
(food.mana.how), rename Cloudflare Pages project.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/CLOUDFLARE_FALLBACK.md

@@ -179,11 +179,11 @@ presi-api.mana.how {
     reverse_proxy 10.0.0.2:3036
 }
 
-nutriphi.mana.how {
+food.mana.how {
     reverse_proxy 10.0.0.2:5017
 }
 
-nutriphi-api.mana.how {
+food-api.mana.how {
     reverse_proxy 10.0.0.2:3037
 }