diff --git a/.github/workflows/canonical-governance.yml b/.github/workflows/canonical-governance.yml
index 51446d8d4..4f6e6e197 100644
--- a/.github/workflows/canonical-governance.yml
+++ b/.github/workflows/canonical-governance.yml
@@ -86,6 +86,19 @@ jobs:
           cache: true
           cache-dependency-path: repos/pulse/go.sum
 
+      - name: Set up Node.js for frontend governance
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version: '20'
+          cache: npm
+          cache-dependency-path: repos/pulse/frontend-modern/package-lock.json
+
+      - name: Install locked frontend governance dependencies
+        working-directory: repos/pulse/frontend-modern
+        env:
+          PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD: '1'
+        run: npm ci --ignore-scripts --no-audit --no-fund
+
       - name: Stub embedded frontend assets for Go tests
         run: bash scripts/ensure_test_assets.sh
 
diff --git a/docs/release-control/v6/internal/CANONICAL_DEVELOPMENT_PROTOCOL.md b/docs/release-control/v6/internal/CANONICAL_DEVELOPMENT_PROTOCOL.md
index e3ae2f067..cb206464c 100644
--- a/docs/release-control/v6/internal/CANONICAL_DEVELOPMENT_PROTOCOL.md
+++ b/docs/release-control/v6/internal/CANONICAL_DEVELOPMENT_PROTOCOL.md
@@ -253,6 +253,14 @@ print a non-passing receipt skeleton with
 `python3 scripts/release_control/browser_verification_guard.py --print-template`
 after staging the intended frontend paths.
 
+A source diff that is byte-for-byte the locked Prettier output of its parent
+has no rendered behavior or visual delta and does not require a new browser
+receipt. The exemption fails closed when the formatter is unavailable or the
+formatted output differs by even one token. Canonical Governance must install
+the lockfile-pinned frontend formatter before evaluating changed commits so a
+clean runner applies the same deterministic exemption as the commit-time
+guard; its guard tests must run with that formatter present rather than skip.
+
 ## Reporter Test Image Validation Path
 
 When a reviewed fix needs live confirmation from one or a few Docker-based
diff --git a/internal/repoctl/canonical_development_protocol_test.go b/internal/repoctl/canonical_development_protocol_test.go
index c788a993b..1e13050f8 100644
--- a/internal/repoctl/canonical_development_protocol_test.go
+++ b/internal/repoctl/canonical_development_protocol_test.go
@@ -1863,6 +1863,10 @@ func TestCanonicalGovernanceRunsInCI(t *testing.T) {
 		"repository: rcourtman/pulse-pro",
 		"repository: rcourtman/pulse-enterprise",
 		"repository: rcourtman/pulse-mobile",
+		"Set up Node.js for frontend governance",
+		"cache-dependency-path: repos/pulse/frontend-modern/package-lock.json",
+		"Install locked frontend governance dependencies",
+		"npm ci --ignore-scripts --no-audit --no-fund",
 		"PULSE_REPO_ROOT_PULSE_PRO",
 		"PULSE_REPO_ROOT_PULSE_ENTERPRISE",
 		"PULSE_REPO_ROOT_PULSE_MOBILE",
@@ -1885,6 +1889,12 @@ func TestCanonicalGovernanceRunsInCI(t *testing.T) {
 		"python3 scripts/release_control/status_audit_test.py",
 		"python3 scripts/release_control/subsystem_lookup_test.py",
 	})
+
+	install := strings.Index(workflow, "Install locked frontend governance dependencies")
+	guard := strings.Index(workflow, "Run canonical completion guard against changed commits")
+	if install < 0 || guard < 0 || install > guard {
+		t.Fatal("locked frontend governance dependencies must be installed before the per-commit browser guard")
+	}
 }
 
 func TestLegacyReleaseControlOrchestratorIsRemoved(t *testing.T) {