test(perf): run benchmarks against built artifacts

AGENTS.md

@@ -50,7 +50,7 @@ packages/    @deepseek-ai/dsh-<pkg> workspaces at packages/<group>/<pkg>/
   util/        zero-dependency utilities
 python/      Python SDK/runtime (see python/README.md)
 native/      @deepseek-ai/node-addon-landlock-run source of record (see native/README.md)
-benchmarks/  cross-package performance gates
+benchmarks/  performance gates
 .agents/     Agent workflows and Agent Notes (`notes/`)
 docs/        architecture, generated catalogs, postmortems, cookbook (see docs/AGENTS.md)
 scripts/     gates and generators