refactor: migrate module path from git.t-juice.club to code.t-juice.club

Update Go module path and all import references to reflect the migration
from Gitea (git.t-juice.club) to Forgejo (code.t-juice.club).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/auth/auth.go

@@ -5,7 +5,7 @@ import (
 	"sync"
 	"time"
 
-	"git.t-juice.club/torjus/oubliette/internal/config"
+	"code.t-juice.club/torjus/oubliette/internal/config"
 )
 
 const (

internal/auth/auth_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"
 
-	"git.t-juice.club/torjus/oubliette/internal/config"
+	"code.t-juice.club/torjus/oubliette/internal/config"
 )
 
 func newTestAuth(acceptAfter int, ttl time.Duration, statics ...config.Credential) *Authenticator {