feat(installer): add badge prompt and auto-create README if missing

- Interactive prompt asks "Add BMAD badge to your README?" (default yes)
- --no-badge skips the prompt and disables badge
- --yes accepts badge by default
- If user wants badge but no README exists, creates README.md with
  project name and badge

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

tools/installer/commands/install.js

@@ -96,7 +96,18 @@ module.exports = {
       }
 
       const config = await ui.promptInstall(options);
-      config.noBadge = options.badge === false;
+
+      // Ask about badge unless --no-badge or --yes
+      if (options.badge === false) {
+        config.noBadge = true;
+      } else if (options.yes) {
+        config.noBadge = false;
+      } else {
+        config.noBadge = !(await prompts.confirm({
+          message: 'Add BMAD badge to your README?',
+          default: true,
+        }));
+      }
 
       // Handle cancel
       if (config.actionType === 'cancel') {

tools/installer/core/badge.js

@@ -73,6 +73,11 @@ function removeBadge(content) {
     .join('\n');
 }
 
+function createReadmeWithBadge(owner, repo, projectName) {
+  const badgeLine = generateBadgeMarkdown(owner, repo);
+  return `# ${projectName}\n\n${badgeLine}\n`;
+}
+
 module.exports = {
   resolveGitRemote,
   findReadme,
@@ -80,4 +85,5 @@ module.exports = {
   generateBadgeMarkdown,
   injectBadge,
   removeBadge,
+  createReadmeWithBadge,
 };

tools/installer/core/installer.js

@@ -1061,7 +1061,12 @@ class Installer {
 
     const readmePath = await badge.findReadme(projectDir);
     if (!readmePath) {
-      addResult('Badge', 'warn', 'no README found');
+      // No README — create one with the badge
+      const projectName = path.basename(projectDir);
+      const content = badge.createReadmeWithBadge(remote.owner, remote.repo, projectName);
+      const newReadmePath = path.join(projectDir, 'README.md');
+      await fs.writeFile(newReadmePath, content, 'utf8');
+      addResult('Badge', 'ok', 'created README.md with badge');
       return;
     }