Initial commit — DRB server stack

Includes c2-core (FastAPI/MQTT/Firestore), discord-bot (slash commands),
frontend (Next.js admin UI), and mosquitto config.

drb-frontend/components/AuthProvider.tsx

@@ -0,0 +1,57 @@
+"use client";
+
+import { createContext, useContext, useEffect, useState } from "react";
+import { onAuthStateChanged, signOut as firebaseSignOut, User } from "firebase/auth";
+import { auth } from "@/lib/firebase";
+
+interface AuthContextType {
+  user: User | null;
+  loading: boolean;
+  isAdmin: boolean;
+  signOut: () => Promise<void>;
+}
+
+const AuthContext = createContext<AuthContextType>({
+  user: null,
+  loading: true,
+  isAdmin: false,
+  signOut: async () => {},
+});
+
+export function AuthProvider({ children }: { children: React.ReactNode }) {
+  const [user, setUser] = useState<User | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [isAdmin, setIsAdmin] = useState(false);
+
+  useEffect(() => {
+    return onAuthStateChanged(auth, async (u) => {
+      setUser(u);
+      setLoading(false);
+
+      if (u) {
+        document.cookie = "drb_session=1; path=/; SameSite=Strict";
+        // Read custom claims to determine admin status
+        const result = await u.getIdTokenResult(true);
+        setIsAdmin(!!result.claims.admin);
+      } else {
+        document.cookie = "drb_session=; path=/; max-age=0";
+        setIsAdmin(false);
+      }
+    });
+  }, []);
+
+  async function signOut() {
+    await firebaseSignOut(auth);
+    document.cookie = "drb_session=; path=/; max-age=0";
+  }
+
+  return (
+    <AuthContext.Provider value={{ user, loading, isAdmin, signOut }}>
+      {children}
+    </AuthContext.Provider>
+  );
+}
+
+export function useAuth() {
+  return useContext(AuthContext);
+}