Expand context for work queues

server: use SO_REUSEADDR for main listener

server: add /query/api-meta.json, docs

server: incorporate queue management

Simplify server module

email: remove leftover debug code

Add email work queue

.builds/alpine.yml: tune verbosity down

Drop leftover references to gql.sr.ht

Add test for internal auth

auth/middleware_test: test invalid auth cookie

Add basic auth tests

auth/middleware: fix printf suspension params

model: import from gql.sr.ht

Import GQL server interfaces from gql.sr.ht

client: import from gql.sr.ht

redis: import middleware from gql.sr.ht

.builds/alpine.yml: run tests

Overhaul crypto module

Part 1 of merging gql.sr.ht with core-go

Add crypto module with depessimised webhook signing from gitsrht-update-hook