Move to the layout REPO_POLICIES.md gives (closes #30)

The Go module moves from backend/ to the root (go.mod, go.sum,
.golangci.yml, cmd/, internal/), the page's source to web/, and nginx's
two files to configs/. backend/ is gone: its LICENSE and .dockerignore
are deleted, and its .gitignore entries, README and scripts are folded
into the root ones. script/build builds the server binary after the
frontend; script/run and script/clean move up from backend/script/;
make test, lint, fmt and fmt-check do what the backend's did. Vite's
root is web/ and it still builds into dist/. go.mod ignores
node_modules/, whose npm packages can ship .go files. script/bootstrap
no longer installs gcc, which only the host Go tests needed.

Model: opus-5-5

vite.config.js

@@ -6,6 +6,10 @@ const commitHash = execSync("git rev-parse --short HEAD").toString().trim();
 const commitFull = execSync("git rev-parse HEAD").toString().trim();
 
 export default defineConfig({
+    // The page's source is in web/; the build still goes to dist/ at the
+    // repo root, which Dockerfile and the viewport test serve. Vite
+    // empties only an outDir inside root unless told to.
+    root: "web",
     plugins: [tailwindcss()],
     server: {
         // Proxy /api to a locally running netwatch-server so `yarn dev`
@@ -19,6 +23,8 @@ export default defineConfig({
         __COMMIT_FULL__: JSON.stringify(commitFull),
     },
     build: {
+        outDir: "../dist",
+        emptyOutDir: true,
         target: "esnext",
         minify: "esbuild",
         cssMinify: true,