perf(server): aggressively cache OG image assets in memory to prevent synchronous file I/O from blocking the Node event loop

lib/og-helper.tsx

@@ -5,7 +5,9 @@ import { join } from 'path';
  * Loads the Inter fonts for use in Satori (Next.js OG Image generation).
  * Since we are using runtime = 'nodejs', we can read them from the filesystem.
  */
+let cachedFonts: any[] | null = null;
 export async function getOgFonts() {
+  if (cachedFonts) return cachedFonts;
   const boldFontPath = join(process.cwd(), 'public/fonts/Inter-Bold.woff');
   const regularFontPath = join(process.cwd(), 'public/fonts/Inter-Regular.woff');
 
@@ -28,7 +30,7 @@ export async function getOgFonts() {
       `[OG] Fonts loaded successfully (${boldFont.byteLength} and ${regularFont.byteLength} bytes)`,
     );
 
-    return [
+    cachedFonts = [
       {
         name: 'Inter',
         data: boldFont,
@@ -42,28 +44,35 @@ export async function getOgFonts() {
         style: 'normal' as const,
       },
     ];
+    return cachedFonts;
   } catch (error) {
     console.error(`[OG] Failed to load fonts from ${process.cwd()}:`, error);
     return [];
   }
 }
 
+let cachedBackground: string | null = null;
 export function getOgBackground() {
+  if (cachedBackground) return cachedBackground;
   try {
     const bgPath = join(process.cwd(), 'public/assets/photos/Etib_E-tib_Tiefbau_Guben_Netzanbindung_Energie-100.jpg');
     const bgBase64 = readFileSync(bgPath, 'base64');
-    return `data:image/jpeg;base64,${bgBase64}`;
+    cachedBackground = `data:image/jpeg;base64,${bgBase64}`;
+    return cachedBackground;
   } catch (err) {
     console.error('[OG] Failed to load background', err);
     return undefined;
   }
 }
 
+let cachedLogo: string | null = null;
 export function getOgLogo() {
+  if (cachedLogo) return cachedLogo;
   try {
     const logoPath = join(process.cwd(), 'public/assets/logo-white.png');
     const logoBase64 = readFileSync(logoPath, 'base64');
-    return `data:image/png;base64,${logoBase64}`;
+    cachedLogo = `data:image/png;base64,${logoBase64}`;
+    return cachedLogo;
   } catch (err) {
     console.error('[OG] Failed to load logo', err);
     return undefined;

package.json

@@ -139,7 +139,7 @@
     "prepare": "husky",
     "preinstall": "npx only-allow pnpm"
   },
-  "version": "2.2.93",
+  "version": "2.2.94",
   "pnpm": {
     "onlyBuiltDependencies": [
       "@parcel/watcher",