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/vite.config.ts

@@ -1,17 +1,33 @@
+/// <reference types="vitest" />
 import { defineConfig } from 'vite'
 import vue from '@vitejs/plugin-vue'
-import { resolve } from 'path'
+import { fileURLToPath, URL } from 'node:url'
 
 export default defineConfig({
   plugins: [vue()],
   resolve: {
     alias: {
-      '@': resolve(__dirname, 'src'),
-    },
+      '@': fileURLToPath(new URL('./src', import.meta.url))
+    }
   },
   base: '/build/',
   build: {
     outDir: '../public/build',
     emptyOutDir: true,
   },
+  test: {
+    environment: 'happy-dom',
+    globals: true,
+    setupFiles: ['./src/test/setup.ts'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'html'],
+      exclude: [
+        'src/components/CropEditor.vue',
+        'src/components/StickerCanvas.vue',
+        'src/assets/**',
+        'src/test/**',
+      ]
+    }
+  }
 })