diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 953726c..5f4330f 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -29,10 +29,30 @@ jobs:
           node-version: '22'
           cache: 'pnpm'
       - run: pnpm install --frozen-lockfile
+
+      # The release gate must validate in the same environment as CI. Without
+      # this, `pnpm test` here runs against a weaker box than ci.yml uses, so a
+      # green CI stops predicting a green release — which is exactly how the
+      # first v0.3.0 tag failed: the deny-all-net fallback test spawns `bwrap`,
+      # and this runner had no bubblewrap installed.
+      # Kept byte-for-byte in step with the "Install sandbox tools" step in
+      # ci.yml; change both together.
+      - name: Install sandbox tools
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y bubblewrap slirp4netns curl
+          sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0 || true
+          sudo sysctl -w net.ipv4.ip_unprivileged_port_start=53 || true
+
       - run: pnpm typecheck
       - run: pnpm lint
       - run: pnpm format:check
-      - run: pnpm test
+      - name: Test
+        # Matches ci.yml: opts in the selective-allowlist integration test, which
+        # self-skips when bwrap/slirp4netns are absent.
+        env:
+          DC_SANDBOX_NET_TEST: '1'
+        run: pnpm test
       - run: pnpm docs:check
       - run: pnpm release:check
 
diff --git a/docs/RELEASING.md b/docs/RELEASING.md
index 0474043..f8232b2 100644
--- a/docs/RELEASING.md
+++ b/docs/RELEASING.md
@@ -69,7 +69,9 @@ git push origin v0.1.3
 
 The `release.yml` workflow fires on any `v*` tag push. Its validation and publication graph is:
 
-1. **validate** — typecheck, lint, format, tests, docs, `pnpm release:check`, and the Playwright
+1. **validate** — installs the same sandbox tooling `ci.yml` does (bubblewrap + slirp4netns; the
+   deny-all-net fallback test spawns `bwrap`), then typecheck, lint, format, tests, docs,
+   `pnpm release:check`, and the Playwright
    desktop protocol journey. The release gate starts the real bundled app-server twice and verifies
    protocol capabilities, thread persistence, thin-client boundaries, bundle budgets, and timing.
 2. **publish-cli** — bumps `apps/cli/package.json` to the tag version,