row329: finish pinned model proxy P1 and record final gate (#1827)

scripts/bus-service.sh

@@ -91,6 +91,14 @@ render() {
     local -a proxy_sed=()
     if [ "$MOSAIC_INSTANCE_PROXY_CONFIGURED" = 1 ]; then
         proxy_sed=(-e "/^Description=/a Wants=$PROXY_UNIT\\nAfter=$PROXY_UNIT")
+        # A configured default instance may have selected an explicit config.
+        # Bind both units to it; no-proxy renders retain their historical bytes.
+        if [ -z "$MOSAIC_UNIT_SUFFIX" ]; then
+            case "$MOSAIC_INSTANCE_CONFIG" in
+                *[!A-Za-z0-9/._+-]*) die "proxy-config-invalid" ;;
+            esac
+            proxy_sed+=(-e "/^Environment=PATH=/a Environment=MOSAIC_CONFIG=$MOSAIC_INSTANCE_CONFIG")
+        fi
     fi
     sed "${proxy_sed[@]}" -e "s|@REPO@|$root|g" -e "s|@PATH@|$path|g" -e "s|@PM_FLAGS@|$pm_flags|g" -e "s|^@CLAUDE_ENV@$|$claude|" "${INSTANCE_SED[@]}" "$TEMPLATE"
 }