Update the agent state file, replacing its contents.

Args: directory: Absolute path to the GitHub worktree or repository directory where the state file should be saved state: The current state description of what the agent is trying to do

Load the current agent state from the state file.

Args: directory: Absolute path to the GitHub worktree or repository directory where the state file is located

Returns: The current state string, or empty string if the file doesn't exist

Append a message to the log file.

Args: directory: Absolute path to the GitHub worktree or repository directory where the log file should be saved message: The message to append to the log

Load the last num_chars characters from the log file.

Args: directory: Absolute path to the GitHub worktree or repository directory where the log file is located num_chars: The number of characters to retrieve from the end of the log

Returns: The last num_chars characters from the log, or the entire log if it's shorter