feat: readded google signins and add global announcement feature

- Updated .env.example to include new environment variables for Google authentication and global announcement settings.
- Integrated Google sign-in functionality in SignInButton and HeroSection components, allowing users to log in with their Google accounts.
- Added GlobalAnnouncement component to display maintenance notices or announcements on the homepage layout.
- Enhanced styling for Google sign-in buttons to improve user experience.

surfsense_web/components/homepage/global-announcement.tsx

@@ -0,0 +1,27 @@
+import { IconInfoCircle } from "@tabler/icons-react";
+import { GLOBAL_ANNOUNCEMENT_ENABLED, GLOBAL_ANNOUNCEMENT_MESSAGE } from "@/lib/env-config";
+
+/**
+ * Small, site-wide banner for planned downtime / maintenance notices.
+ *
+ * Controlled entirely through build-time env vars so it can be toggled from
+ * Vercel without a code change:
+ *   - NEXT_PUBLIC_GLOBAL_ANNOUNCEMENT_ENABLED ("true" to show)
+ *   - NEXT_PUBLIC_GLOBAL_ANNOUNCEMENT_MESSAGE (the copy to display)
+ */
+export function GlobalAnnouncement() {
+	const message = GLOBAL_ANNOUNCEMENT_MESSAGE.trim();
+
+	if (!GLOBAL_ANNOUNCEMENT_ENABLED || !message) {
+		return null;
+	}
+
+	return (
+		<div className="fixed bottom-0 left-0 right-0 z-60 w-full bg-amber-500/15 text-amber-900 backdrop-blur-md dark:bg-amber-400/10 dark:text-amber-200 border-t border-amber-500/30">
+			<div className="mx-auto flex max-w-7xl items-center justify-center gap-2 px-4 py-2 text-center text-sm font-medium">
+				<IconInfoCircle className="h-4 w-4 shrink-0" />
+				<span>{message}</span>
+			</div>
+		</div>
+	);
+}

surfsense_web/components/homepage/hero-section.tsx

@@ -37,8 +37,38 @@ import {
 	getAssetLabel,
 	usePrimaryDownload,
 } from "@/lib/desktop-download-utils";
+import { BUILD_TIME_AUTH_TYPE, buildBackendUrl } from "@/lib/env-config";
+import { trackLoginAttempt } from "@/lib/posthog/events";
 import { cn } from "@/lib/utils";
 
+const GoogleLogo = ({ className }: { className?: string }) => (
+	<svg
+		className={className}
+		viewBox="0 0 24 24"
+		xmlns="http://www.w3.org/2000/svg"
+		role="img"
+		aria-label="Google logo"
+	>
+		<title>Google logo</title>
+		<path
+			d="M22.56 12.25c0-.78-.07-1.53-.2-2.25H12v4.26h5.92c-.26 1.37-1.04 2.53-2.21 3.31v2.77h3.57c2.08-1.92 3.28-4.74 3.28-8.09z"
+			fill="#4285F4"
+		/>
+		<path
+			d="M12 23c2.97 0 5.46-.98 7.28-2.66l-3.57-2.77c-.98.66-2.23 1.06-3.71 1.06-2.86 0-5.29-1.93-6.16-4.53H2.18v2.84C3.99 20.53 7.7 23 12 23z"
+			fill="#34A853"
+		/>
+		<path
+			d="M5.84 14.09c-.22-.66-.35-1.36-.35-2.09s.13-1.43.35-2.09V7.07H2.18C1.43 8.55 1 10.22 1 12s.43 3.45 1.18 4.93l2.85-2.22.81-.62z"
+			fill="#FBBC05"
+		/>
+		<path
+			d="M12 5.38c1.62 0 3.06.56 4.21 1.64l3.15-3.15C17.45 2.09 14.97 1 12 1 7.7 1 3.99 3.47 2.18 7.07l3.66 2.84c.87-2.6 3.3-4.53 6.16-4.53z"
+			fill="#EA4335"
+		/>
+	</svg>
+);
+
 type HeroUseCase = {
 	id: string;
 	title: string;
@@ -284,6 +314,31 @@ export function HeroSection() {
 }
 
 function GetStartedButton() {
+	const isGoogleAuth = BUILD_TIME_AUTH_TYPE === "GOOGLE";
+	const [isRedirecting, setIsRedirecting] = useState(false);
+
+	const handleGoogleLogin = () => {
+		if (isRedirecting) return;
+		setIsRedirecting(true);
+		trackLoginAttempt("google");
+		window.location.href = buildBackendUrl("/auth/google/authorize-redirect");
+	};
+
+	if (isGoogleAuth) {
+		return (
+			<Button
+				type="button"
+				variant="ghost"
+				onClick={handleGoogleLogin}
+				disabled={isRedirecting}
+				className="h-14 w-full cursor-pointer gap-3 rounded-lg border border-white bg-white text-center text-base font-medium text-[#1f1f1f] shadow-sm transition duration-150 hover:bg-zinc-100 hover:text-[#1f1f1f] sm:w-56 dark:border-white"
+			>
+				<GoogleLogo className="h-5 w-5" />
+				<span>Continue with Google</span>
+			</Button>
+		);
+	}
+
 	return (
 		<Button
 			asChild