fix(shell): keep Cursor on agent and Grok on grok

Grok's installer prepends ~/.grok/bin and steals ~/.local/bin/agent.
easyzsh already shims `grok`; claim `agent` for Cursor and drop the
vendor bin from PATH so a later Grok upgrade cannot shadow it.

.zshenv

@@ -27,6 +27,21 @@ if [[ -d "$ZSH_ALWAYS_ON_DIR" ]]; then
     . "$f"
   done
 fi
+
+# Cursor owns `agent` when installed. Grok is only ~/.local/bin/grok.
+# Grok's installer also writes ~/.local/bin/agent and may prepend ~/.grok/bin.
+_easyzsh_agent=
+[[ -L $HOME/.local/bin/agent ]] && _easyzsh_agent=$(readlink $HOME/.local/bin/agent)
+if [[ -x $HOME/.local/bin/cursor-agent ]]; then
+  if [[ ! -e $HOME/.local/bin/agent || $_easyzsh_agent == *'/.grok/'* ]]; then
+    ln -sfn $HOME/.local/bin/cursor-agent $HOME/.local/bin/agent
+  fi
+elif [[ -L $HOME/.local/bin/agent && $_easyzsh_agent == *'/.grok/'* ]]; then
+  rm -f $HOME/.local/bin/agent
+fi
+unset _easyzsh_agent
+path=(${path:#$HOME/.grok/bin})
+
 if [[ -f "$ZSH_ALWAYS_ON_DIR/local.zsh" ]]; then
   # shellcheck disable=SC1090
   . "$ZSH_ALWAYS_ON_DIR/local.zsh"