fix: resize images to 2550 px (300 DPI) at build time to prevent WSL2 OOM crash

4096×4096 source images decoded simultaneously by Chromium consumed ~3.2 GB,
exhausting WSL2 RAM. Build now uses sharp to downsize to 2550×2550 (8.5 in ×
300 DPI) into output/resized/ before Puppeteer loads them, cutting in-memory
footprint to ~1.25 GB. Also adds all story images (01–12) to the repository.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/build.js

@@ -1,9 +1,10 @@
-import { readdir, readFile, writeFile, access } from 'fs/promises';
+import { readdir, readFile, writeFile, access, mkdir } from 'fs/promises';
 import { join, resolve, dirname } from 'path';
 import { fileURLToPath } from 'url';
 import matter from 'gray-matter';
 import { marked } from 'marked';
 import nunjucks from 'nunjucks';
+import sharp from 'sharp';
 
 const __dir = dirname(fileURLToPath(import.meta.url));
 const root = resolve(__dir, '..');
@@ -11,12 +12,39 @@ const root = resolve(__dir, '..');
 // Nunjucks: load templates relative to project root
 const env = nunjucks.configure(join(root, 'templates'), { autoescape: true });
 
+const PRINT_PX = 2550; // 8.5 in × 300 DPI
+
 async function fileExists(path) {
   try { await access(path); return true; } catch { return false; }
 }
 
+// Resize image to PRINT_PX on the long side, write to output/resized/ tree.
+// Returns the resized file path (absolute). Skips resize if already ≤ PRINT_PX.
+async function resizeForPrint(srcAbs, resizedDir) {
+  const rel   = srcAbs.replace(root + '/', '');            // e.g. images/01/scene-1.png
+  const dest  = join(resizedDir, rel);
+  const destDir = dirname(dest);
+
+  await mkdir(destDir, { recursive: true });
+
+  const meta = await sharp(srcAbs).metadata();
+  const maxDim = Math.max(meta.width || 0, meta.height || 0);
+
+  if (maxDim <= PRINT_PX) {
+    // Already small enough — copy as-is
+    await sharp(srcAbs).toFile(dest);
+  } else {
+    await sharp(srcAbs)
+      .resize(PRINT_PX, PRINT_PX, { fit: 'inside', withoutEnlargement: true })
+      .png({ compressionLevel: 6 })
+      .toFile(dest);
+  }
+  return dest;
+}
+
 async function loadStories() {
-  const contentDir = join(root, 'content');
+  const contentDir  = join(root, 'content');
+  const resizedDir  = join(root, 'output', 'resized');
   const files = (await readdir(contentDir)).filter(f => f.endsWith('.md')).sort();
 
   const stories = [];
@@ -27,18 +55,24 @@ async function loadStories() {
 
     if (data.type === 'front-matter') continue;
 
-    // Split body by --- into individual scene texts
     const sceneTexts = content.split(/\n---\n/).map(t => t.trim()).filter(Boolean);
 
     const scenes = await Promise.all(
       (data.scenes || []).map(async (scene, i) => {
-        const imagePath = join(root, scene.image);
-        const imageExists = await fileExists(imagePath);
+        const srcAbs = join(root, scene.image);
+        const imageExists = await fileExists(srcAbs);
+
+        let imageSrc = `../${scene.image}`;
+        if (imageExists) {
+          await resizeForPrint(srcAbs, resizedDir);
+          // Relative path from output/book.html to output/resized/
+          imageSrc = `resized/${scene.image}`;
+        }
+
         return {
           ...scene,
           imageExists,
-          // Relative path from output/book.html back to project root
-          image: `../${scene.image}`,
+          image: imageSrc,
           html: marked.parse(sceneTexts[i] || ''),
         };
       })