feat: add authentication system (login, users, auth middleware)

- server/auth.js: JWT middleware and auth routes
- src/stores/auth.js + useAuthFetch.js: client-side auth state
- src/views/LoginView.vue + UsersView.vue: login and user management UI
- router, sidebar, App.vue: guard routes behind auth
- COOLIFY.md: add real deployment IDs

src/composables/useAuthFetch.js

@@ -0,0 +1,15 @@
+import { useAuthStore } from "../stores/auth";
+
+export function useAuthFetch() {
+  function authFetch(url, options = {}) {
+    const auth = useAuthStore();
+    const headers = {
+      "Content-Type": "application/json",
+      ...(options.headers || {}),
+    };
+    if (auth.token) headers["Authorization"] = `Bearer ${auth.token}`;
+    return fetch(url, { ...options, headers });
+  }
+
+  return { authFetch };
+}