Stop the slow test packages waiting (closes #263)

The slowest test packages spent their time waiting rather than testing.

db.Params gains an optional PasswordCost (zero means bcrypt.DefaultCost), and the db, ircserver and handlers tests hash at bcrypt.MinCost. A test IRC server's relay checks its queue on broker notification instead of polling. The service and handlers tests build config.Config directly and run in parallel; config exports DefaultTrustedProxies and ParseTrustedProxies for them. Fixed sleeps give way to waits for the event. Production defaults are unchanged.

What still takes time is CPU work under -race or a timeout a test is about.

Model: opus-5-5

internal/handlers/export_test.go

@@ -6,6 +6,10 @@ import (
 	"sneak.berlin/go/neoirc/internal/db"
 )
 
+// MaxLongPollTimeout is the longest HandleGetMessages waits, in
+// seconds.
+const MaxLongPollTimeout = maxLongPollTimeout
+
 // SetPollMessages makes HandleGetMessages read the client
 // output queue with poll in place of Database.PollMessages.
 func (hdlr *Handlers) SetPollMessages(