Previously, if an incoming request caused a crash, we would just drop it
on the floor. We should at least have the decency to serve the client a
quick 500 and let them get on with their day.
We make sure not to touch state here. The connection is guaranteed-fresh
because of the task's semantics, and we're handling it in-line in one go.
Notably we only give a simple "crud!" for the body, instead of the full
error trace. We don't know whether the request is authenticated or not
(and who knows if checking was the cause of the crash!), and the crud
might leak sensitive details about the ship it occurred on. For the
owner, the trace still gets printed into the terminal.
Adds a "mode" to channels, which can be set to either %json (current
behavior) or %jam. For %jam channels, aside from the SSE framing, all
communication happens through @uw-encoded jammed nouns. This applies to
both outgoing channel events, as well as incoming channel requests.
We choose @uw-style encoding because raw bytestreams are fragile and
cannot work inside the SSE stream context.
Currently, a separate endpoint (/~/channel-jam/etc) is used to indicate
%jam as the desired mode for a channel. We will probably want to make
this a bit cleaner, not least because it's not currently implemented as
a formal standalone endpoint, but also to give it stronger aesthetic
equivalence with the existing channel endpoint. Putting the mode in the
file extension is a tempting option here, but semantically not quite
right.
Connecting to the same channel across multiple modes is currently
supported, but it's untested, and unclear whether this is desirable or
not.
The previous changes implementing the /~/name endpoint were breaking,
since we changed the type of `$action:eyre`. This commit keeps the /~/name
endpoint functional, but adds adapters to eyre scries that returns the old
`$action:eyre` type. These adapters and their associated intermediate types
can be removed the next time we burn a kelvin.
