🐛 fix(playbook): use relative paths in CLAUDE.md when not at project root

When CLAUDE.md lives in a subdirectory (e.g. .claude/CLAUDE.md), the
@AGENTS.md import must use ../AGENTS.md since Claude Code resolves @path
relative to the file's directory. Calculate depth automatically.

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

scripts/playbook.py

@@ -746,11 +746,20 @@ def sync_claude_md(project_root: Path, config: dict) -> None:
         if claude_md is None:
             claude_md = project_root / "CLAUDE.md"
 
+    rel_prefix = ""
+    try:
+        rel = claude_md.parent.resolve().relative_to(project_root.resolve())
+        if rel != Path("."):
+            depth = len(rel.parts)
+            rel_prefix = "../" * depth
+    except ValueError:
+        pass
+
     block_lines = [
         _CLAUDE_BLOCK_START,
         "",
-        "@AGENTS.md",
-        "@AGENT_RULES.md",
+        f"@{rel_prefix}AGENTS.md",
+        f"@{rel_prefix}AGENT_RULES.md",
         "",
         _CLAUDE_BLOCK_END,
     ]