add dark grey to seed_palette

this also fixes the symbols not lining up on the template styles (there's another gray)

packages/server/src/tools/seed_palette.ts

@@ -23,6 +23,10 @@ async function main() {
       name: "Deep Grey",
       hex: "4B4F58",
     },
+    {
+      name: "Dark Grey",
+      hex: "1F1E26",
+    },
     {
       name: "Black",
       hex: "000000",