test(plugin-security): declare the registry log level for the suite (check:registry-log-declared)

The declared-positions seeder's suite now constructs a SchemaRegistry to
read the registry's own by-name precedence, which puts plugin-security in
check:registry-log-declared's population. Declare OS_REGISTRY_LOG: 'warn'
as the gate prescribes; the engine's shipped default is unchanged.

Claude-Session: https://claude.ai/code/session_01WMQprn46CND82KmY8sZWBu
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/plugins/plugin-security/vitest.config.ts

@@ -14,6 +14,12 @@ export default defineConfig({
     disableConsoleIntercept: true,
     globals: true,
     environment: 'node',
+    // #13517: quiet the registry's per-item registration chatter — the
+    // engine's own `OS_REGISTRY_LOG` seam, not a change to its shipped
+    // default. Enforced by scripts/check-registry-log-declared.mjs: the
+    // declared-positions seeder's suite constructs a `SchemaRegistry` to read
+    // the registry's own by-name precedence.
+    env: { OS_REGISTRY_LOG: 'warn' },
   },
   resolve: {
     // [#8577] Both entries exist for `suggested-audience-bindings-install-path.test.ts`,