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>

src/paired-execution-context.test.ts

@@ -48,6 +48,19 @@ vi.mock('./logger.js', () => ({
   },
 }));
 
+// This suite verifies the flag-OFF ("by default") carry-forward behavior. Pin
+// the switch to false so the result is deterministic regardless of the
+// deployment's .env override (the flag-ON path is covered separately in
+// paired-execution-context-carry-forward.test.ts).
+vi.mock('./config.js', async () => {
+  const actual =
+    await vi.importActual<typeof import('./config.js')>('./config.js');
+  return {
+    ...actual,
+    PAIRED_CARRY_FORWARD_LATEST_OWNER_FINAL: false,
+  };
+});
+
 import * as db from './db.js';
 import * as config from './config.js';
 import {