Pin carry-forward flag off in default-behavior test; ignore test scratch

The "does not carry forward by default" test in paired-execution-context.test.ts
read the real config, so enabling PAIRED_CARRY_FORWARD_LATEST_OWNER_FINAL in
this deployment's .env flipped its result and it failed. Pin the flag to false
in that suite (mirroring the flag-on carry-forward.test.ts which pins true) so
the unit test is deterministic regardless of the ambient .env. Full suite is
green again with the flag enabled: 1595 pass / 3 skip / 0 fail.

Also gitignore the .ejclaw-*images-*/ and .ejclaw-attachment-*/ scratch dirs
that outbound-attachments tests create in the repo root; they only leak when a
test run is interrupted mid-flight and would otherwise clutter git status.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitignore

@@ -16,6 +16,10 @@ data/
 data-*/
 logs/
 .ejclaw-reviewer-runtime/
+# Scratch dirs created in CWD by outbound-attachments tests; leak into the repo
+# root only when a test run is interrupted mid-flight.
+.ejclaw-attachment-*/
+.ejclaw-*images-*/
 
 # Groups - only track base structure and specific CLAUDE.md files
 groups-*/