Remote / foldkit-remote-server

Diagnostics

A server answers some failures without telling the caller why. Each is a typed diagnostic, reported through Diagnostics.Reporter (foldkit-surface's channel, re-exported by foldkit-remote), which by default is Effect's log:

`_tag`	`level`	When
`ServerDefect`	`error`	Something on this side broke (a layer, a resolver, a handler's defect) and the caller was answered `Internal error`; it carries the `cause`.
`AnswerUnread`	`warning`	A mutation committed, but reading its answer failed: the client reads those rows again.
`PublishFailed`	`error`	A mutation committed, but its live publish failed: live subscribers do not hear it.
`ClockSkewed`	`warning`	A write's time was past `clockSkew` from the server's clock (a client clock that is off, or a durable write that waited), so the server wrote its own; it carries `sent`, `own` and `bound`.

Provide another reporter as any service: Layer.succeed(Diagnostics.Reporter, report) in the layer the handlers run in. serveFetch takes one with the request beside it, used for everything that request runs, a broken layer included:

serveFetch({
  server,
  resolvePrincipal,
  layer: (env: Env) => databaseLayer(env),
  diagnostics: (diagnostic, request) =>
    Effect.logError(`${request.method} ${request.url}: ${diagnostic.message}`),
})

In a test, Diagnostics.collect() gives a reporter and the array it fills.