STATE-WP-0093-T08: reader-aware mark-read and notice ack in the instruction templates; first standing notice live.

No fleet regeneration: standing notices are already visible to agents on
old instructions, and the notice carries its own ack command.

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

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 63291@bnt-lap001
Assistant-Session: 8bd77868-ca68-4f49-bb1e-d539ecc0d703

scripts/project_rules/session-protocol.template

@@ -31,8 +31,10 @@ Without MCP tools:
 ```bash
 curl -s "http://127.0.0.1:8000/messages/?to_agent={REPO_SLUG}&unread_only=true" \
   | python3 -m json.tool
-curl -s -X PATCH "http://127.0.0.1:8000/messages/<id>/read" \
+curl -s -X PATCH "http://127.0.0.1:8000/messages/<id>/read?reader={REPO_SLUG}" \
   -H "Content-Type: application/json" -d '{}'
+# Standing notices (to_agent "broadcast", kind "standing") stay until acknowledged:
+# curl -s -X POST "http://127.0.0.1:8000/messages/<id>/ack" -H "Content-Type: application/json" -d '{"agent":"{REPO_SLUG}"}'
 ```
 
 **Step 3 — Scan workplans**