feat(build): integrate frontend build into backend binary and update scripts

frontend/.gitignore

@@ -1,4 +1,3 @@
 node_modules/
-dist/
 *.local
 .DS_Store

frontend/README.md

@@ -24,14 +24,14 @@ The dev server proxies `/api` (and the log websocket) to the backend. By default
 $env:NUKUMIZU_API = "http://192.168.20.4:8080"; npm run dev
 ```
 
-Production build (static assets only):
+Production build:
 
 ```bash
-npm run build      # outputs dist/
+npm run build      # outputs ../web/dist
 npm run preview
 ```
 
-The backend does not serve static files, so put `dist/` behind any static server and proxy `/api` (and `ws://…/api/system/getLogs`) to the Nukumizu backend.
+Vite writes to `../web/dist` rather than `frontend/dist` (see `build.outDir` in `vite.config.js`) because the Go backend embeds that directory into the binary — `go:embed` cannot reach outside the package it sits in, so the output has to live under `web/`. The repo's `build-*` scripts run this build for you and compile the backend afterwards; `npm run build` alone does not change what an already-built binary serves.
 
 ## API contract notes
 

frontend/vite.config.js

@@ -6,6 +6,16 @@ const BACKEND = process.env.NUKUMIZU_API || 'http://127.0.0.1:8080';
 
 export default defineConfig({
     plugins: [vue()],
+    build: {
+        // web/embed.go embeds this directory into the Go binary. It has to live
+        // inside the web package: go:embed cannot reach outside its own
+        // directory, so ../web/dist is as close as it gets.
+        outDir: '../web/dist',
+        // The directory is outside the project root, so Vite refuses to empty
+        // it unless told to. Without this, stale hashed assets from earlier
+        // builds pile up in the binary.
+        emptyOutDir: true
+    },
     server: {
         host: '0.0.0.0',
         port: 5173,