feat(sasch40): polish retro game layout, clean tavern scene, and improve mobile HUD

- Hide GameBoy D-Pad and action buttons during RPG and dialogue modes
- Add prequel intro landing screen for QR code arrivals with Haumdaucher lore
- Clean baked-in text from tavern scene background and streamline navigation bar
- Add safe-zone margins and HTML HUD in platformer and party express acts
- Optimize Certificate modal layout and scoring breakdown for mobile screens
- Add automated end-to-end browser playtest script with Puppeteer
- Accelerate Docker build via native pre-compilation

projects/sasch40/frontend/package.json

@@ -18,6 +18,7 @@
     "@types/canvas-confetti": "^1.9.0",
     "@types/node": "^22.10.2",
     "@vitejs/plugin-vue": "^5.2.1",
+    "puppeteer-core": "^25.12.0",
     "typescript": "^5.7.2",
     "vite": "^6.0.3",
     "vue-tsc": "^2.2.0"