fix: og image with resvg client

lib/og.js

@@ -8,7 +8,7 @@
  */
 
 import satori from "satori";
-import { Resvg } from "@resvg/resvg-js";
+import { spawnSync } from "node:child_process";
 import {
   readFileSync,
   writeFileSync,
@@ -482,12 +482,20 @@ export async function generateOgImages(contentDir, cacheDir, siteName, batchSize
 
     const card = buildCard(title, description, date, postType, siteName);
     const svg = await satori(card, { width: WIDTH, height: HEIGHT, fonts });
-    const resvg = new Resvg(svg, {
-      fitTo: { mode: "width", value: WIDTH },
-    });
-    const pngBuffer = resvg.render().asPng();
-
-    writeFileSync(join(ogDir, `${slug}.png`), pngBuffer);
+    // Render SVG to PNG using the system resvg CLI
+    // Requires: pkg install resvg
+    const outPath = join(ogDir, `${slug}.png`);
+    const resvgProc = spawnSync(
+      "resvg",
+      ["-w", String(WIDTH), "-b", COLORS.bg, "-o", outPath, "-"],
+      { input: svg, encoding: "buffer" }
+    );
+    if (resvgProc.error) {
+      throw resvgProc.error;
+    }
+    if (resvgProc.status !== 0) {
+      throw new Error(`resvg CLI failed: ${resvgProc.stderr?.toString()}`);
+    }
     newManifest[slug] = { title: slug, hash };
     generated++;