Rebrand to Sage & Cream identity, working contact form, drop Firebase

- New sage/cream palette and stacked logo lockup (The Vine over Coffeehouse
  + Bakery) driven by currentColor; logo SVGs now colorable
- Reuse the logo component for the hero and section marks
- Rewrite site copy: real founding (Morissa Bennett, 2024), real story from
  the product range, remove invented claims and AI phrasing
- Contact form now sends over SMTP via /api/contact (nodemailer) with real
  send/error states, server-side validation, and reply-to the customer;
  delivers to CONTACT_TO. Add .env.example and a test-email script
- Fix mobile: unmount the off-screen menu (killed sideways scroll), cap logo
  width, responsive heroes and type
- Remove Firebase (config, tracked build output, placeholder pages, nix
  firebase-tools) now that hosting has moved
- Delete dead code: LoyaltyCardForm, ProductModal, LoadingSpinner, card-flip
  CSS, unused Playfair font
- Serve dev/start on port 2024

package.json

@@ -3,16 +3,16 @@
   "version": "0.1.0",
   "private": true,
   "scripts": {
-    "dev": "next dev",
+    "dev": "next dev -p 2024",
     "build": "next build",
-    "start": "next start",
+    "start": "next start -p 2024",
     "lint": "next lint"
   },
   "dependencies": {
     "@svgr/webpack": "^8.1.0",
     "framer-motion": "^11.11.11",
-    "keen-slider": "^6.8.6",
-    "next": "^16.1.6",
+    "next": "^16.2.10",
+    "nodemailer": "^9.0.3",
     "react": "^19.0.0",
     "react-awesome-slider": "^4.1.0",
     "react-dom": "^19.0.0",
@@ -20,6 +20,7 @@
   },
   "devDependencies": {
     "@types/node": "^20",
+    "@types/nodemailer": "^8.0.1",
     "@types/react": "^18",
     "@types/react-dom": "^18",
     "eslint": "^9.39.2",