Route spawn sub-agents through daemon by default.

⛰️ Features

• (acp) Route spawn sub-agents through daemon by default (#705)
• (cli) Add cloud API command (#718)
• (routing) Adaptive, self-optimizing policy-table routing (#710)

🐛 Bug Fixes

• (sdk) Preserve upstream bad requests (#716)

🚜 Refactor

• Remove attestation, fold plugins/ into crates/ (#701)
• Relocate bitrouter-mcp crate under crates/ (#704)