test(audit): lock phase0 rolling script TAG wiring

Add regression tests that verify rolling and rolling:prune scripts keep shared overridable TAG semantics and tagged prune reports. No architecture/protocol flow changes; diagram files reviewed and no updates were needed.

src/audit/phase0BaselineScriptWiring.test.ts

@@ -0,0 +1,36 @@
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+import { describe, expect, it } from 'vitest';
+
+interface PackageManifest {
+  scripts?: Record<string, string>;
+}
+
+function loadPackageScripts(): Record<string, string> {
+  const raw = readFileSync(resolve(process.cwd(), 'package.json'), 'utf8');
+  const manifest = JSON.parse(raw) as PackageManifest;
+  return manifest.scripts ?? {};
+}
+
+describe('phase0 baseline script wiring', () => {
+  it('keeps rolling script TAG override semantics', () => {
+    const scripts = loadPackageScripts();
+    const rolling = scripts['audit:phase0-baseline:live:refresh:drift:rolling'];
+
+    expect(rolling).toBeDefined();
+    expect(rolling).toContain('TAG=${TAG:-$(date -u +%F-%H%M%S)}');
+    expect(rolling).toContain('--tag "$TAG"');
+    expect(rolling).toContain('--report-tag "$TAG"');
+  });
+
+  it('keeps rolling prune script on shared overridable TAG', () => {
+    const scripts = loadPackageScripts();
+    const rollingPrune = scripts['audit:phase0-baseline:live:refresh:drift:rolling:prune'];
+
+    expect(rollingPrune).toBeDefined();
+    expect(rollingPrune).toContain('TAG=${TAG:-$(date -u +%F-%H%M%S)}');
+    expect(rollingPrune).not.toContain('TAG=$(date -u +%F-%H%M%S)');
+    expect(rollingPrune).toContain('pnpm audit:phase0-baseline:live:refresh:drift:rolling');
+    expect(rollingPrune).toContain('--report-tag "$TAG"');
+  });
+});