tcm's server host, `#tcm/host` (host protocol 1): what a server API library needs of the process. The call being answered, the app's SQLite files (their tables as tcm keeps them), the lock every table call and transaction takes on the store, transactions, the job queue with its worker and schedules, the wire codec and the schema checker. One per process, however many libraries call it. Its own source is written to `.tcm/cache/tcm-host.js`, so it uses only what comes in through `deps`.