feat(export): site.webmanifest/robots.txt 자동 생성 및 extras 포함 (TDD)

lib/exporter/extras.ts

@@ -6,6 +6,24 @@ export function buildExtrasForPage(page: Page): Record<string, Uint8Array> {
   const extras: Record<string, Uint8Array> = {}
   const te = new TextEncoder()
 
+  // Always provide a baseline robots.txt
+  const robots = `User-agent: *\nDisallow:`
+  extras['robots.txt'] = te.encode(robots)
+
+  // Provide a minimal site.webmanifest derived from Page
+  try {
+    const name = page.title || 'App'
+    const short = name.length > 12 ? name.slice(0, 12) : name
+    const manifest = {
+      name,
+      short_name: short,
+      start_url: '/',
+      display: 'standalone',
+      theme_color: page.theme?.primaryColor ?? '#000000',
+    }
+    extras['site.webmanifest'] = te.encode(JSON.stringify(manifest))
+  } catch {}
+
   const hasAction = !!(page.form?.actionUrl && page.form.actionUrl.trim().length > 0)
   if (!hasAction) {
     const code = `// Google Apps Script (Code.gs)