A SimpleX Chat bot that answers arithmetic (closes #1)

Remove the template's HTTP service, database and fx wiring. Add exact
arithmetic on go/parser and go/constant, a client that runs simplex-chat
as a child process and drives its WebSocket API, and the bot, which keeps
an auto-accepting address and replies to each message. The image adds the
checksum-pinned simplex-chat v7.0.2 on Ubuntu 22.04.

Model: opus-5-5

internal/config/export_test.go

@@ -11,7 +11,3 @@ package config
 //
 //nolint:gochecknoglobals // a test seam, not mutable state.
 var Load = load
-
-// CSRFKeyBytes is the required key length, so the tests can assert on
-// it without restating the number.
-const CSRFKeyBytes = csrfKeyBytes