chore: stage all in-progress work before repo split

Web app: new entities (Image, RenderedAsset, SharedImage, Token,
DeviceImageHistory), enums, repositories, controllers, message handlers,
migrations, tests, frontend upload/library/sticker UI, Vue components.

Firmware: EPD background screen binaries + gen scripts, setup_bg header.

Infra: ddev config, test bundle, gitignore coverage dir.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/package.json

@@ -6,20 +6,31 @@
   "scripts": {
     "dev": "vite",
     "build": "vue-tsc -b && vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage"
   },
   "dependencies": {
+    "konva": "^10.3.0",
     "pinia": "^3.0.4",
     "sass": "^1.99.0",
     "vue": "^3.5.32",
+    "vue-konva": "^3.4.0",
     "vue-router": "^4.6.4"
   },
   "devDependencies": {
     "@types/node": "^24.12.2",
     "@vitejs/plugin-vue": "^6.0.6",
+    "@vitest/coverage-v8": "^4.1.5",
+    "@vue/test-utils": "^2.4.10",
     "@vue/tsconfig": "^0.9.1",
+    "happy-dom": "^20.9.0",
+    "jsdom": "^29.1.1",
+    "msw": "^2.14.3",
     "typescript": "~6.0.2",
     "vite": "^8.0.10",
+    "vitest": "^4.1.5",
     "vue-tsc": "^3.2.7"
   }
 }