feat(deploy): configurable backend HOST + env-driven vite base/assetsDir

- backend: HOST env (default 127.0.0.1, dev-safe; 0.0.0.0 in container)
- frontend: VITE_BASE drives base/assetsDir/manifest for portal embedding
- backward compatible: no env => identical to previous behavior

backend/src/config.ts

@@ -1,5 +1,5 @@
 export interface AppConfig {
-  port: number; harnessDir: string; thtBin: string; piBin: string;
+  host: string; port: number; harnessDir: string; thtBin: string; piBin: string;
   authMode: "none" | "mock" | "oidc";
   defaults: { provider?: string; model?: string; thinking?: string };
   maxPiProcesses: number;
@@ -8,6 +8,7 @@ export interface AppConfig {
 }
 export function loadConfig(env: Record<string, string | undefined>): AppConfig {
   return {
+    host: env.HOST ?? "127.0.0.1",
     port: Number(env.PORT ?? 8787),
     harnessDir: env.THT_HARNESS_DIR ?? "../harness",
     thtBin: env.THT_BIN ?? "tht",

backend/src/server.ts

@@ -2,5 +2,5 @@ import { buildApp } from "./app.js";
 import { loadConfig } from "./config.js";
 const config = loadConfig(process.env);
 const app = buildApp(config);
-app.listen({ port: config.port, host: "127.0.0.1" })
+app.listen({ port: config.port, host: config.host })
   .then((addr) => console.log(`backend listening on ${addr}`));

backend/test/config.test.ts

@@ -0,0 +1,20 @@
+import { test, expect } from "vitest";
+import { loadConfig } from "../src/config.js";
+
+test("loadConfig espone host con default dev-safe 127.0.0.1", () => {
+  expect(loadConfig({})).toMatchObject({ host: "127.0.0.1" });
+});
+
+test("loadConfig rispetta HOST esplicito (necessario in container)", () => {
+  expect(loadConfig({ HOST: "0.0.0.0" })).toMatchObject({ host: "0.0.0.0" });
+});
+
+test("loadConfig merge altri campi con l'host", () => {
+  expect(
+    loadConfig({ HOST: "0.0.0.0", THT_BIN: "/opt/venv/bin/tht", PORT: "9000" })
+  ).toMatchObject({
+    host: "0.0.0.0",
+    thtBin: "/opt/venv/bin/tht",
+    port: 9000,
+  });
+});

frontend/vite.config.ts

@@ -2,11 +2,15 @@ import { defineConfig } from "vite";
 import react from "@vitejs/plugin-react";
 import path from "path";
 
-export default defineConfig({
-  plugins: [react()],
-  resolve: {
-    alias: {
-      "@": path.resolve(__dirname, "./src"),
-    },
-  },
+export default defineConfig(() => {
+  const embedBase = process.env.VITE_BASE; // "/datamart-builder/assets/" in embedded; undefined = standalone
+  return {
+    plugins: [react()],
+    // base: prefisso pubblico degli asset. Default "/" (standalone).
+    // assetsDir vuoto in embedded → asset alla root di dist/ così il proxy
+    // /datamart-builder/assets/ → frontend-root mappa 1:1 (niente /assets/assets/).
+    base: embedBase ?? "/",
+    build: { manifest: true, outDir: "dist", assetsDir: embedBase ? "" : "assets" },
+    resolve: { alias: { "@": path.resolve(__dirname, "./src") } },
+  };
 });