Persist media uploads outside public/ to survive rebuilds and redeploys

Move media storage from public/assets/images/media to storage/media
(outside Git and public/), so uploaded images, favicons and logos are
preserved across rebuilds and git clean. Add a shared media-storage helper,
update the upload/serve actions and API routes, and gitignore storage/.

src/actions/save-logo.ts

@@ -5,8 +5,9 @@ import path from "node:path";
 import { revalidatePath } from "next/cache";
 import { prisma } from "@/lib/prisma";
 import { siteSettings } from "@/lib/services/site-settings";
+import { resolveMediaPath } from "@/lib/media-storage";
 
-const MEDIA_DIR = "public/assets/images/media/logo";
+const MEDIA_DIR = resolveMediaPath("logo");
 
 export async function saveLogo(
 	formData: FormData,
@@ -26,7 +27,7 @@ export async function saveLogo(
 							? "webp"
 							: "png";
 		const filename = `logo-${Date.now()}-${Math.random().toString(36).slice(2, 8)}.${ext}`;
-		const baseDir = path.resolve(process.cwd(), MEDIA_DIR);
+		const baseDir = MEDIA_DIR;
 		const filePath = path.resolve(baseDir, filename);
 		if (!filePath.startsWith(baseDir + path.sep)) {
 			return { success: false, error: "Invalid path" };
@@ -80,7 +81,7 @@ export async function saveLogoFromUrl(
 							? "webp"
 							: "gif";
 		const filename = `logo-${Date.now()}-${Math.random().toString(36).slice(2, 8)}.${ext}`;
-		const baseDir = path.resolve(process.cwd(), MEDIA_DIR);
+		const baseDir = MEDIA_DIR;
 		const filePath = path.resolve(baseDir, filename);
 		if (!filePath.startsWith(baseDir + path.sep)) {
 			return { success: false, error: "Invalid path" };