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/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." });