Initial project skeleton

Haskell backend: Orb HTTP framework, JSON-only API
Frontend: Mithril.js SPA with TypeScript, Neo Brutalism CSS
Dockerized build via flipstone/haskell-tools image

Routes:
  GET /api/health — health check

Build: ./hs stack build
Test:  ./hs stack test
Run:   ./scripts/run

frontend/src/api.ts

@@ -0,0 +1,21 @@
+/**
+ * Thin API client for the Sis backend.
+ */
+
+const BASE = "/api";
+
+async function request<T>(path: string): Promise<T> {
+  const resp = await fetch(BASE + path);
+  if (!resp.ok) {
+    throw new Error(`HTTP ${resp.status}: ${resp.statusText}`);
+  }
+  return resp.json() as Promise<T>;
+}
+
+export interface HealthResponse {
+  message: string;
+}
+
+export function checkHealth(): Promise<string> {
+  return request<HealthResponse>("/health").then((r) => r.message);
+}

frontend/src/components/App.ts

@@ -0,0 +1,35 @@
+import m, { Vnode } from "mithril";
+
+import { checkHealth } from "../api";
+
+interface AppAttrs {}
+
+interface AppState {
+  health: string;
+}
+
+export const App: m.Component<AppAttrs, AppState> = {
+  oninit(vnode: Vnode<AppAttrs, AppState>) {
+    vnode.state.health = "loading...";
+    checkHealth()
+      .then((msg) => {
+        vnode.state.health = msg;
+        m.redraw();
+      })
+      .catch((err) => {
+        vnode.state.health = "error: " + String(err);
+        m.redraw();
+      });
+  },
+
+  view(vnode: Vnode<AppAttrs, AppState>) {
+    return m("main.container", { style: { maxWidth: "720px", margin: "2rem auto" } }, [
+      m("h1", "Sis"),
+      m("p", "Shared household chore tracker."),
+      m("p", [
+        m("strong", "API status: "),
+        m("span", vnode.state.health),
+      ]),
+    ]);
+  },
+};

frontend/src/index.ts

@@ -0,0 +1,8 @@
+import m from "mithril";
+
+import { App } from "./components/App";
+
+const root = document.getElementById("app");
+if (root) {
+  m.mount(root, App);
+}