feat(lib): use new challenge creation flow

Previously Anubis constructed challenge strings from request metadata.
This was a good idea in spirit, but has turned out to be a very bad idea
in practice. This new flow reuses the Store facility to dynamically
create challenge values with completely random data.

This is a fairly big rewrite of how Anubis processes challenges. Right
now it defaults to using the in-memory storage backend, but on-disk
(boltdb) and valkey-based adaptors will come soon.

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/challenge/challengetest/challengetest.go

@@ -0,0 +1,23 @@
+package challengetest
+
+import (
+	"testing"
+	"time"
+
+	"github.com/TecharoHQ/anubis/internal"
+	"github.com/TecharoHQ/anubis/lib/challenge"
+	"github.com/google/uuid"
+)
+
+func New(t *testing.T) *challenge.Challenge {
+	t.Helper()
+
+	id := uuid.Must(uuid.NewV7())
+	randomData := internal.SHA256sum(time.Now().String())
+
+	return &challenge.Challenge{
+		ID:         id.String(),
+		RandomData: randomData,
+		IssuedAt:   time.Now(),
+	}
+}

lib/challenge/challengetest/challengetest_test.go

@@ -0,0 +1,7 @@
+package challengetest
+
+import "testing"
+
+func TestNew(t *testing.T) {
+	_ = New(t)
+}