feat: use custom CLAUDE.md template path when creating cases

When creating new cases via /api/cases or /api/quick-start, the
server now checks ~/.claudeman/settings.json for a defaultClaudeMdPath.
If found and the file exists, it uses that template with placeholder
substitution ([PROJECT_NAME], [PROJECT_DESCRIPTION], [DATE]).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/templates/claude-md.ts

@@ -1,6 +1,23 @@
-export function generateClaudeMd(caseName: string, description: string = ''): string {
+import { existsSync, readFileSync } from 'node:fs';
+
+export function generateClaudeMd(caseName: string, description: string = '', templatePath?: string): string {
   const date = new Date().toISOString().split('T')[0];
 
+  // If a custom template path is provided and exists, use it
+  if (templatePath && existsSync(templatePath)) {
+    try {
+      let template = readFileSync(templatePath, 'utf-8');
+      // Replace placeholders with actual values
+      template = template.replace(/\[PROJECT_NAME\]/g, caseName);
+      template = template.replace(/\[PROJECT_DESCRIPTION\]/g, description || 'A new project');
+      template = template.replace(/\[DATE\]/g, date);
+      return template;
+    } catch (err) {
+      console.error(`Failed to read template from ${templatePath}:`, err);
+      // Fall through to default template
+    }
+  }
+
   return `# CLAUDE.md - Project Configuration
 
 ## Project Overview

src/web/server.ts

@@ -577,7 +577,9 @@ export class WebServer extends EventEmitter {
         mkdirSync(casePath, { recursive: true });
         mkdirSync(join(casePath, 'src'), { recursive: true });
 
-        const claudeMd = generateClaudeMd(name, description || '');
+        // Read settings to get custom template path
+        const templatePath = this.getDefaultClaudeMdPath();
+        const claudeMd = generateClaudeMd(name, description || '', templatePath);
         writeFileSync(join(casePath, 'CLAUDE.md'), claudeMd);
 
         this.broadcast('case:created', { name, path: casePath });
@@ -620,7 +622,9 @@ export class WebServer extends EventEmitter {
           mkdirSync(casePath, { recursive: true });
           mkdirSync(join(casePath, 'src'), { recursive: true });
 
-          const claudeMd = generateClaudeMd(caseName, '');
+          // Read settings to get custom template path
+          const templatePath = this.getDefaultClaudeMdPath();
+          const claudeMd = generateClaudeMd(caseName, '', templatePath);
           writeFileSync(join(casePath, 'CLAUDE.md'), claudeMd);
 
           this.broadcast('case:created', { name: caseName, path: casePath });
@@ -806,6 +810,21 @@ export class WebServer extends EventEmitter {
     this.broadcast('respawn:timerStarted', { sessionId, durationMinutes, endAt, startedAt: now });
   }
 
+  // Helper to get custom CLAUDE.md template path from settings
+  private getDefaultClaudeMdPath(): string | undefined {
+    const settingsPath = join(homedir(), '.claudeman', 'settings.json');
+    try {
+      if (existsSync(settingsPath)) {
+        const content = readFileSync(settingsPath, 'utf-8');
+        const settings = JSON.parse(content);
+        return settings.defaultClaudeMdPath || undefined;
+      }
+    } catch (err) {
+      console.error('Failed to read settings:', err);
+    }
+    return undefined;
+  }
+
   private async startScheduledRun(prompt: string, workingDir: string, durationMinutes: number): Promise<ScheduledRun> {
     const id = uuidv4();
     const now = Date.now();