round 1: implement bracket-first manual compaction

examples/package.json

@@ -14,6 +14,7 @@
     "@deepseek-ai/dsh-bash-sandbox": "workspace:*",
     "@deepseek-ai/dsh-cli-demo": "workspace:*",
     "@deepseek-ai/dsh-code-runtime-worker": "workspace:*",
+    "@deepseek-ai/dsh-command-compact": "workspace:*",
     "@deepseek-ai/dsh-compact-basic": "workspace:*",
     "@deepseek-ai/dsh-compact-tool-result-prune": "workspace:*",
     "@deepseek-ai/dsh-fs-local": "workspace:*",