Prepare a Dot-Prefixed Workspace and Bash History Controls

Prepare a local Linux workspace by creating or resetting the mode of a dot-prefixed directory under /dev/shm; independently, in a Bash session, change that shell's history settings. The directory command creates no files and sets an existing target's mode to 0700. A leading dot hides a directory from ordinary listings only; /dev/shm mount and swap behavior vary. Bash history changes apply to the current Bash process and do not remove records already written elsewhere or suppress independent logging. The two actions have no output/input dependency.