✨ feat(playbook): auto-create CLAUDE.md with path discovery

sync_claude_md now:
- Checks project root CLAUDE.md first, then .claude/CLAUDE.md
- Auto-creates if neither exists (default: project root)
- Supports playbook.claude_md config to override location
- Update test to verify auto-creation behavior

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/playbook.py

@@ -721,18 +721,30 @@ def sync_agents_template(context: dict) -> int:
         date_value,
         playbook_scripts,
     )
-    sync_claude_md(project_root)
+    sync_claude_md(project_root, context.get("config", {}))
     return 0
 
 
 _CLAUDE_BLOCK_START = "<!-- playbook:claude:start -->"
 _CLAUDE_BLOCK_END = "<!-- playbook:claude:end -->"
 
+_CLAUDE_MD_CANDIDATES = ["CLAUDE.md", ".claude/CLAUDE.md"]
 
-def sync_claude_md(project_root: Path) -> None:
-    claude_md = project_root / "CLAUDE.md"
-    if not claude_md.exists():
-        return
+
+def sync_claude_md(project_root: Path, config: dict) -> None:
+    claude_md_config = config.get("playbook", {}).get("claude_md")
+
+    claude_md: Path | None = None
+    if claude_md_config:
+        claude_md = project_root / claude_md_config
+    else:
+        for candidate in _CLAUDE_MD_CANDIDATES:
+            path = project_root / candidate
+            if path.exists():
+                claude_md = path
+                break
+        if claude_md is None:
+            claude_md = project_root / "CLAUDE.md"
 
     block_lines = [
         _CLAUDE_BLOCK_START,
@@ -743,6 +755,12 @@ def sync_claude_md(project_root: Path) -> None:
         _CLAUDE_BLOCK_END,
     ]
 
+    if not claude_md.exists():
+        ensure_dir(claude_md.parent)
+        claude_md.write_text("\n".join(block_lines) + "\n", encoding="utf-8")
+        log(f"Created {claude_md.relative_to(project_root)} with playbook block.")
+        return
+
     text = claude_md.read_text(encoding="utf-8")
 
     if _CLAUDE_BLOCK_START in text: