MAS-WP-0003-T04: Google Groups results (lower-cases members); T04 done

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 252470@bnt-lap001
Assistant-Session: ad628c8f-4be2-4979-94c9-76c7ed6f8241

workplans/MAS-WP-0003-provider-live-test.md

@@ -167,7 +167,7 @@ address and what envelope recipient arrives.
 
 ```task
 id: MAS-WP-0003-T04
-status: progress
+status: done
 priority: medium
 state_hub_task_id: "97c88b4f-14c3-5f6c-8f31-6b9fc3afd236"
 ```
@@ -188,7 +188,17 @@ or are stripped.
   separator; the operator endorses the mapping) and SCP-7 (case-robust
   identifiers).
   Gmail forwarding: skipped (optional; would only add a second forwarder
-  that accepts `=`). Still open: one mailing list (VERP).
+  that accepts `=`).
+- 2026-10-18, Google Groups (`coulomb-social@googlegroups.com`): the member
+  form accepted `ticket=GS-85QJ8WC09P+comments@` unchanged. The invitation
+  (11:58:20Z) arrived byte-identical and was correlated; no auto-reply was
+  sent (Auto-Submitted). After acceptance, the list post (12:05:37Z)
+  arrived for the **lower-cased** `ticket=gs-85qj8wc09p+comments@`. Its
+  envelope sender was `coulomb-social+bnc…@googlegroups.com`, which does
+  not collide with our syntax, and the facet survived. Exact comparison
+  missed the ticket, so the post was quarantined with no reply
+  (Precedence: list). Correct per v0.1, but lost to the ticket. This is
+  the second provider to lower-case, so SCP-7 is now the highest priority.
 
 ## Cap total outbound mail