docs(plan): add Phase 4 items to the two-machine field-test checklist

Also re-triggers CI: run 165 on 1d038be died to rust-lld crashes from disk
exhaustion on the runner host (12G free vs ~12G cold-build transient), not a
code failure; 18G of local build artifacts have been swept (30G free now).

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

docs/chat-hardening-plan.md

@@ -355,6 +355,10 @@ it; do not make ordinary unit tests depend on external network access.
   stress run; verify leave/reconnect controls remain responsive.
 - [ ] Linux and Windows URL opening for valid links; malformed/userinfo links remain
   selectable but do not launch.
+- [ ] A message with more than eight URLs renders eight clickable links and the
+  rest as selectable plain text, with nothing dropped.
+- [ ] A message attempting bidi-override display spoofing renders in send order
+  (the override characters are stripped, emoji/joining-script text intact).
 
 ## Completion criteria