agent brief: verify merges in snapshots instead of the main tree

notes/dev/wave-2026-11-07.md

@@ -7,8 +7,11 @@
   current version (never blindly overwrite a file another agent may have changed meanwhile).
 - Do NOT commit (the coordinator commits after each package). Do not touch git in the main tree.
 - Build in your own copy: `JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64 ./gradlew spotlessApply build fatJar`.
-  After copy-back run `JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64 ./gradlew spotlessApply build` in the main tree
-  once; if it fails only because of another agent's half-merged change, wait a few minutes and retry.
+  NEVER run gradle in ~/projects/llamamod itself (parallel builds clash in build/test-results). After copy-back,
+  verify with a fresh snapshot: `rsync -a --exclude build --exclude .gradle --exclude re/proj --exclude out
+  ~/projects/llamamod/ $CLAUDE_JOB_DIR/tmp/<agent>/snap/` and build/test there (then delete the snapshot).
+  If it fails only because of another agent's half-merged change, wait a few minutes and retry. The coordinator
+  runs the main-tree build.
 - Every behaviour change needs a test (unit test where possible) and, for UI, a screenshot check on YOUR display;
   for game-side changes an in-game check with tools/apptest.py (your display, session names prefixed with your name).
 - Keep user-facing texts English, short and plain. Update the relevant notes/*.md and, if users see the change,