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.

.zshrc

@@ -148,3 +148,9 @@ alias j="z"
 if (( $+functions[k] )); then
     alias k="k -h"
 fi
+
+# Grok CLI may prepend ~/.grok/bin (its `agent` shadows Cursor).
+path=(${path:#$HOME/.grok/bin})
+if [[ -x $HOME/.local/bin/cursor-agent ]]; then
+    alias agent=$HOME/.local/bin/cursor-agent
+fi