Initial commit: Tortugotchi sea turtle conservation PWA

Vanilla HTML/CSS/JS Tamagotchi-style game with three species
(green, loggerhead, leatherback), persistent idle progression,
hazard QTEs (sharks, boats, ghost nets, tourists), and offline
PWA support via service worker. Includes README with cited
conservation resources and research.

manifest.json

@@ -0,0 +1,27 @@
+{
+  "id": "/",
+  "short_name": "Tortugotchi",
+  "name": "Tortugotchi: Sea Turtle Protector",
+  "description": "A Tamagotchi-style game to protect nests, raise sea turtles, and advocate for sea turtle conservation.",
+  "icons": [
+    {
+      "src": "icon-192.png",
+      "type": "image/png",
+      "sizes": "192x192",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "icon-512.png",
+      "type": "image/png",
+      "sizes": "512x512",
+      "purpose": "any maskable"
+    }
+  ],
+  "scope": "./",
+  "start_url": "./index.html",
+  "background_color": "#0d1b2a",
+  "theme_color": "#008080",
+  "display": "standalone",
+  "orientation": "portrait-primary",
+  "categories": ["games", "education"]
+}