Add missing opencode.json for Hugh — fix permission auto-reject

Hugh (opencode_local) had no opencode.json, so opencode defaulted
to rejecting file access outside his cwd. This blocked him from
accessing .github/workflows/ in other repos.

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

engineering/hugh/opencode.json

@@ -0,0 +1,7 @@
+{
+  "$schema": "https://opencode.ai/config.json",
+  "permission": "allow",
+  "experimental": {
+    "snapshots": false
+  }
+}