Add Nocturne debug web UI, core process control, and web QR login

poc/src/auth-service.ts

@@ -0,0 +1,81 @@
+/*
+ * Veskslop daemon — auth state for the web UI.
+ *
+ * Owns at most one QR login session. The terminal tool and the web UI share
+ * the session class. The token file stays the single credential store.
+ */
+
+import { existsSync } from "node:fs";
+
+import { isTerminalQrState, QrLoginSession, type QrLoginState, type QrLoginUpdate } from "./qr-session.js";
+
+export interface AuthSessionSnapshot {
+    state: QrLoginState;
+    url?: string;
+    user?: object;
+    error?: string;
+    captcha?: object;
+}
+
+export interface AuthStatus {
+    tokenFile: string;
+    hasToken: boolean;
+    session: AuthSessionSnapshot | null;
+}
+
+export class AuthService {
+    private session?: QrLoginSession;
+    private snapshot: AuthSessionSnapshot | null = null;
+    private freshLogin = false;
+
+    constructor(
+        private readonly tokenFile: string,
+        private readonly onUpdate?: (update: QrLoginUpdate) => void
+    ) {}
+
+    status(): AuthStatus {
+        return {
+            tokenFile: this.tokenFile,
+            hasToken: existsSync(this.tokenFile),
+            session: this.snapshot ? structuredClone(this.snapshot) : null
+        };
+    }
+
+    startQr(): AuthStatus {
+        if (this.session && !isTerminalQrState(this.session.state)) return this.status();
+
+        this.snapshot = { state: "connecting" };
+        this.session = new QrLoginSession({
+            tokenFile: this.tokenFile,
+            debug: process.env.DEBUG === "1",
+            onUpdate: update => {
+                this.snapshot = { ...update };
+                if (update.state === "finished") this.freshLogin = true;
+                this.onUpdate?.(update);
+            }
+        });
+        this.session.start();
+
+        return this.status();
+    }
+
+    cancelQr(): AuthStatus {
+        this.session?.cancel();
+        return this.status();
+    }
+
+    submitCaptcha(key: string): boolean {
+        return this.session?.submitCaptcha(key) ?? false;
+    }
+
+    /** True once after a successful login. Used to force the new token on start. */
+    consumeFreshLogin(): boolean {
+        const value = this.freshLogin;
+        this.freshLogin = false;
+        return value;
+    }
+
+    clearFreshLogin(): void {
+        this.freshLogin = false;
+    }
+}