fix(shell): clean up rcfiles and remove redundancies

- Remove deprecated GREP_OPTIONS (handled via alias)
- Quote $ZSH_COMPDUMP to prevent word splitting
- Remove duplicate vim alias (nvim alias takes precedence)
- Consolidate completion path to ZSH_CUSTOM_COMPLETION_PATH
- Simplify PATH setup in rcfiles, centralize in exports
- Move LM Studio PATH from rcfiles to exports
- Add clarifying comments for macOS-specific ssh-add

config/exports

@@ -282,7 +282,8 @@ export LESSHISTFILE="$XDG_STATE_HOME"/less/history
 export MANPAGER="less -X"
 
 # Always enable colored `grep` output
-export GREP_OPTIONS="--color=auto"
+# Note: GREP_OPTIONS is deprecated since GNU grep 2.21
+# Color is handled via alias in config/alias
 
 # check the window size after each command and, if necessary,
 # update the values of LINES and COLUMNS.
@@ -436,6 +437,10 @@ msg "Setting up Wakatime configuration"
 export WAKATIME_HOME="$XDG_STATE_HOME/wakatime"
 x-dc "$WAKATIME_HOME"
 
+# LM Studio CLI
+msg "Setting up LM Studio configuration"
+export PATH="$PATH:$HOME/.lmstudio/bin"
+
 # Misc
 msg "Setting up miscellaneous configuration"
 export ZSHZ_DATA="$XDG_STATE_HOME/z"