feat(security): add CSRF protection for all state-changing API routes

- Synchronizer token stored in session; GET /auth/csrf to obtain it
- csrfProtection middleware requires X-CSRF-Token on non-safe methods
- customFetch injects the header via setCsrfTokenGetter
- toolrate boot loads token; reload after local login (session regenerate)
- OpenAPI GET /auth/csrf + CsrfToken schema, orval regenerated

artifacts/api-server/src/middleware/csrf.ts

@@ -0,0 +1,25 @@
+import crypto from "node:crypto";
+import type { Request, Response, NextFunction } from "express";
+
+const SAFE_METHODS = new Set(["GET", "HEAD", "OPTIONS", "TRACE"]);
+
+export function getCsrfToken(req: Request): string {
+  if (!req.session.csrfToken) {
+    req.session.csrfToken = crypto.randomBytes(24).toString("hex");
+  }
+  return req.session.csrfToken;
+}
+
+export function csrfProtection(req: Request, res: Response, next: NextFunction): void {
+  if (SAFE_METHODS.has(req.method.toUpperCase())) {
+    next();
+    return;
+  }
+  const provided = req.headers["x-csrf-token"];
+  const token = getCsrfToken(req);
+  if (typeof provided === "string" && provided && provided === token) {
+    next();
+    return;
+  }
+  res.status(403).json({ error: "CSRF token missing or invalid" });
+}

artifacts/api-server/src/routes/auth.ts

@@ -8,6 +8,7 @@ import { logger } from "../lib/logger";
 import { writeAuditLog } from "../lib/audit";
 import { loginRateLimit, passwordRateLimit } from "../lib/rate-limit";
 import { getEntitlements, requireFeature } from "../middleware/feature";
+import { getCsrfToken } from "../middleware/csrf";
 
 const router: IRouter = Router();
 
@@ -109,6 +110,10 @@ router.get("/auth/mode", (_req, res): void => {
   res.json({ mode: isOidcConfigured() ? "oidc" : "local" });
 });
 
+router.get("/auth/csrf", (req, res): void => {
+  res.json({ token: getCsrfToken(req) });
+});
+
 router.post("/auth/login", loginRateLimit, async (req, res): Promise<void> => {
   if (isOidcConfigured()) {
     res.status(400).json({ error: "Use OIDC login when Keycloak is configured." });

artifacts/api-server/src/routes/index.ts

@@ -8,9 +8,12 @@ import usersRouter from "./users";
 import auditRouter from "./audit";
 import costsRouter from "./costs";
 import adminRouter from "./admin";
+import { csrfProtection } from "../middleware/csrf";
 
 const router: IRouter = Router();
 
+router.use(csrfProtection);
+
 router.use(authRouter);
 router.use(healthRouter);
 router.use(toolsRouter);

artifacts/api-server/src/types/session.d.ts

@@ -14,5 +14,6 @@ declare module "express-session" {
     codeVerifier?: string;
     returnTo?: string;
     oidcState?: string;
+    csrfToken?: string;
   }
 }

artifacts/toolrate/src/App.tsx

@@ -1,7 +1,9 @@
 import { Switch, Route, Router as WouterRouter } from "wouter";
+import { useEffect } from "react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { I18nextProvider } from "react-i18next";
 import i18n from "@/i18n";
+import { loadCsrfToken } from "@/lib/csrf";
 import { Toaster } from "@/components/ui/toaster";
 import { TooltipProvider } from "@/components/ui/tooltip";
 
@@ -50,6 +52,9 @@ function Router() {
 }
 
 function App() {
+  useEffect(() => {
+    void loadCsrfToken();
+  }, []);
   return (
     <I18nextProvider i18n={i18n}>
       <QueryClientProvider client={queryClient}>

artifacts/toolrate/src/lib/csrf.ts

@@ -0,0 +1,27 @@
+import { setCsrfTokenGetter } from "@workspace/api-client-react";
+
+let token: string | null = null;
+
+setCsrfTokenGetter(() => token);
+
+export function getCsrfToken(): string | null {
+  return token;
+}
+
+export async function loadCsrfToken(): Promise<string | null> {
+  try {
+    const res = await fetch(`/api/auth/csrf`, {
+      credentials: "include",
+    });
+    if (!res.ok) {
+      token = null;
+      return null;
+    }
+    const data = (await res.json()) as { token?: string };
+    token = data.token ?? null;
+    return token;
+  } catch {
+    token = null;
+    return null;
+  }
+}

artifacts/toolrate/src/pages/login.tsx

@@ -6,6 +6,7 @@ import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { PasswordInput } from "@/components/password-input";
+import { loadCsrfToken } from "@/lib/csrf";
 import { Card, CardContent, CardHeader, CardTitle, CardDescription } from "@/components/ui/card";
 import { ThemeToggle } from "@/components/theme-toggle";
 import { Wrench, AlertCircle } from "lucide-react";
@@ -33,6 +34,7 @@ export default function Login() {
       {
         onSuccess: () => {
           queryClient.invalidateQueries();
+          void loadCsrfToken();
           setLocation(returnTo);
         },
         onError: (err) => {