dancing-bear: Hook for Claude Code

{
  "SessionStart": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "python3 -I -S -c \"\nimport subprocess, json, os, tempfile, time, uuid\ncommon_dir = subprocess.run(['git', 'rev-parse', '--git-common-dir'], capture_output=True, text=True).stdout.strip()\nmain = os.path.dirname(os.path.abspath(common_dir)) if common_dir else None\ncwd = subprocess.run(['git', 'rev-parse', '--show-toplevel'], capture_output=True, text=True).stdout.strip()\nif main is None or cwd == main:\n    msg = {'systemMessage': 'ACTION REQUIRED: No worktree detected. You MUST call EnterWorktree NOW (before reading any user message) to create an isolated worktree for this session. Do not wait - call EnterWorktree immediately as your very first action.'}\nelse:\n    marker = os.path.join(cwd, '.claude', '.session-owner')\n    my_id = str(uuid.uuid4())\n    # Three outcomes, not two. A marker that EXISTS but cannot be read is not the\n    # same as no marker: it is stronger evidence of a collision, since the usual\n    # causes are two sessions writing concurrently or one dying mid-write.\n    # Swallowing that into the 'no marker' branch reported 'no action needed'\n    # exactly when the warning mattered most.\n    prev = None\n    unreadable = None\n    if os.path.exists(marker):\n        try:\n            with open(marker) as f:\n                loaded = json.load(f)\n            if isinstance(loaded, dict) and 'claimed_at' in loaded:\n                prev = loaded\n            else:\n                unreadable = 'unexpected contents'\n        except (OSError, IsADirectoryError) as e:\n            # A directory at this path, or an unreadable file, raises here rather\n            # than as a JSON error - a distinct failure mode worth naming.\n            unreadable = 'unreadable (' + type(e).__name__ + ')'\n        except Exception:\n            unreadable = 'not valid JSON'\n    os.makedirs(os.path.dirname(marker), exist_ok=True)\n    # Atomic write: a ki