hc: write current_node_arrow_color into hc_settings.json

Every key hcschema declares is now present in the file, so the whole
configuration can be read and edited there rather than half of it living
only in the DEFAULTS merge.

Co-Authored-By: Claude Opus 5 <[email protected]>

 hc_settings.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hc_settings.json b/hc_settings.json
index f326908..07d4236 100644
--- a/hc_settings.json
+++ b/hc_settings.json
@@ -35,6 +35,7 @@
         "node_color": "#607070",
         "zoom_center": "hc_cursor",
         "hcnetcursor": true,
+        "current_node_arrow_color": "#618f8f",
         "grid_x_step": 1.99,
         "grid_y_step": 0.99,
         "node_center_offset_x": 0.5,