Verify daemon identity before session-cli restarts it

[benvinegar]

Summary

• persist a per-daemon identity record and expose an instance id in /health
• only restart the daemon when the health payload matches a trusted Hunk-managed daemon record
• keep compatibility with already-running legacy daemons by verifying the target pid still looks like a hunk ... mcp serve process on Linux

Testing

• bun run typecheck
• bun run lint
• bun test test/daemon-record.test.ts test/mcp-server.test.ts test/session-commands.test.ts
• bun test test/session-cli.test.ts -t "list/get/context expose live Hunk sessions through the daemon"
• bun test test/mcp-e2e.test.ts -t "a live Hunk session auto-starts the daemon and renders CLI comments inline"