chore: gitignore root test-results + leaked marketing dry-run outputs (#599)

Two untracked-and-unignored artifact paths were leaking into git status:
- /test-results/ — root Playwright run dir (the per-app website + cockpit
  ones were already ignored; the root one was missed).
- marketing/channels/marketing/cowork/outbox/dry-runs/ — ephemeral channel
  dry-run simulations (each file carries "simulatedAt"). A shorter
  marketing/cowork/outbox/dry-runs/ path already has a committed .gitignore
  convention; this anchors the deeper doubled path the tool writes to.

No tracked files affected.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: blove

.gitignore

@@ -16,6 +16,10 @@ tmp/
 apps/website/test-results/
 apps/website/public/demo/
 cockpit/**/angular/test-results/
+/test-results/
+
+# Marketing channel dry-run simulation outputs (ephemeral; see "simulatedAt")
+marketing/channels/marketing/cowork/outbox/dry-runs/
 
 # Env
 .env