add root SSH config for git.hanson.xyz to on_start.sh

Ensures git push works without GIT_SSH_COMMAND override. Idempotent —
skips if Host entry already exists in /root/.ssh/config.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

system/clearpilot/on_start.sh

@@ -26,6 +26,18 @@ if [[ $serial == 3889765b ]] && [[ ! -f "$ssh_dir/id_ed25519" || ! -f "$ssh_dir/
     echo "SSH identity keys installed to $ssh_dir"
 fi
 
+# Ensure root SSH config has git.hanson.xyz entry
+if ! grep -q "Host git.hanson.xyz" "$ssh_dir/config" 2>/dev/null; then
+    sudo tee -a "$ssh_dir/config" > /dev/null <<'SSHCFG'
+
+Host git.hanson.xyz
+    IdentityFile /root/.ssh/id_ed25519
+    StrictHostKeyChecking no
+SSHCFG
+    sudo chmod 600 "$ssh_dir/config"
+    echo "SSH config updated for git.hanson.xyz"
+fi
+
 # Always ensure WiFi radio is on
 nmcli radio wifi on 2>/dev/null