fix: cd into runner dir before start so CWD-based discovery works

start_runner() was launching run.sh via absolute path without cd-ing
into the runner directory first. The Runner.Listener process inherited
the SSH login shell CWD (user home dir), so find_pids() CWD matching
always failed for runners started this way.

Fix: cd into $dir before running ./run.sh so the process CWD matches
what find_pids() expects. Relative log path follows automatically.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Spencer Bryngelson

misc/frontier/config.sh

@@ -92,7 +92,7 @@ find_node() {
 start_runner() {
     local node="$1" dir="$2"
     timeout 15 ssh $SSH_OPTS "$node" \
-        "setsid nohup $dir/run.sh >> $dir/runner.log 2>&1 < /dev/null &" \
+        "cd $dir && setsid nohup ./run.sh >> runner.log 2>&1 < /dev/null &" \
         </dev/null 2>/dev/null || true
     sleep 3
     [ -n "$(find_pids "$node" "$dir")" ]