Ignore other harnesses' generated config before it appears

These directories are empty today, so git shows nothing and the gap is
invisible. The moment the sync writes into one, a routine running
git add -A commits another harness's generated config, and the harness
audit then fails after the fact rather than before it. Paths are the
canonical untrackedConsumerPaths list, anchored to the repo root so a
same-named source file deeper in the tree is not caught.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -48,3 +48,12 @@ gfpgan/
 
 # Local evaluation data
 .local-eval/
+
+# Other harnesses' generated config. Claude's sync owns these; a committed copy
+# is a second source nobody reconciles. Anchored so a same-named source file
+# deeper in the tree is not caught.
+/.agents/
+/.codex/
+/.opencode/
+/opencode.json
+/opencode.jsonc