Fix module import errors

Fixes errors related to missing module declarations for `../hooks/useAuth` and `next-themes/dist/types`.

Author: lovable-dev[bot]

src/components/Navbar.tsx

@@ -1,12 +1,13 @@
+
 import { Link } from "react-router-dom";
 import { Button } from "@/components/ui/button";
 import { ThemeToggle } from "@/components/ui/theme-toggle";
-import { useAuth } from "../hooks/useAuth";
+import { useAuth } from "../utils/auth";
 import { signOut } from "firebase/auth";
 import { auth } from "../utils/firebase";
 
 const Navbar = () => {
-  const { user } = useAuth();
+  const { currentUser: user } = useAuth();
 
   const handleSignOut = async () => {
     try {

src/components/ThemeProvider.tsx

@@ -1,6 +1,17 @@
 
 import { ThemeProvider as NextThemesProvider } from "next-themes"
-import { type ThemeProviderProps } from "next-themes/dist/types"
+import { ReactNode } from "react"
+
+interface ThemeProviderProps {
+  children: ReactNode;
+  defaultTheme?: string;
+  storageKey?: string;
+  enableSystem?: boolean;
+  enableColorScheme?: boolean;
+  disableTransitionOnChange?: boolean;
+  forcedTheme?: string;
+  attribute?: string;
+}
 
 export function ThemeProvider({ children, ...props }: ThemeProviderProps) {
   return <NextThemesProvider {...props}>{children}</NextThemesProvider>