docs(framework): canonize merge-authority policy (hard gate 13 + E2E gate note) (#537)

packages/mosaic/framework/guides/E2E-DELIVERY.md

@@ -88,6 +88,11 @@ For implementation work, you MUST run this cycle in order:
 
 ### Post-PR Hard Gate (Execute Sequentially, No Exceptions)
 
+> **Merge authority:** if a coordinator/orchestrator session is active for this
+> work, obtain the coordinator's merge go-ahead after review passes, then run
+> the gate (AGENTS.md hard gate "Merge authority"). Solo delivery proceeds
+> without asking.
+
 1. `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose merge -B main`
 2. `~/.config/mosaic/tools/git/pr-merge.sh -n <PR_NUMBER> -m squash`
 3. `~/.config/mosaic/tools/git/pr-ci-wait.sh -n <PR_NUMBER>`