Add menu-select and case-insensitive tab completion, increase history
size to 50000 with dedup and cross-session sharing, enable useful shell
options (CORRECT, INTERACTIVE_COMMENTS, EXTENDED_GLOB, AUTO_CD), and
fix $home typo in PATH.
Use ZSH_CONFIG instead of ZDOTDIR to avoid conflicts with zsh internals
(e.g. tmux). Register custom word-movement widgets with zle -N, remove
incorrect TERM="konsole" export, add local.zsh config loading, and add
~/.local/bin to PATH.
