fix: correct sprite font vertical offset and use avg char width fallback

src/components/public/logo-generator.tsx

@@ -47,7 +47,7 @@ export default function LogoGenerator() {
     getFontInfo(styleName)
       .then((info) => {
         if (cancelled) return;
-        const canvas = renderToCanvas(info.chars, info.h, info.sheet, safeText, 12);
+        const canvas = renderToCanvas(info.chars, info.h, info.top, info.sheet, safeText, info.avgW);
         if (canvas && canvasRef.current) {
           canvasRef.current.width = canvas.width;
           canvasRef.current.height = canvas.height;
@@ -108,7 +108,7 @@ export default function LogoGenerator() {
       for (const font of allFonts) {
         try {
           const info = await getFontInfo(font.styleName);
-          const canvas = renderToCanvas(info.chars, info.h, info.sheet, safeText, 12);
+          const canvas = renderToCanvas(info.chars, info.h, info.top, info.sheet, safeText, info.avgW);
           if (!canvas) { fail++; continue; }
           const blob = await new Promise<Blob | null>((r) => canvas.toBlob((b) => r(b), "image/png"));
           if (blob) folder.file(`${font.styleName}.png`, blob);