chore: initial project scaffold with admin web, backend, desktop client, and deployment setup

Add monorepo structure for NexaVPN WireGuard control plane including:
- .gitignore for node_modules, build artifacts, and environment files
- README with project overview, monorepo layout, and quick start guide
- Admin web UI with React, Vite, TypeScript, and nginx reverse proxy
- API client with type definitions for users, devices, policies, gateways, and audit logs
- Admin pages for dashboard, users, devices, policies, g

backend/internal/audit/repository.go

@@ -0,0 +1,70 @@
+package audit
+
+import (
+	"context"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type PGRepository struct {
+	db *pgxpool.Pool
+}
+
+func NewPGRepository(db *pgxpool.Pool) *PGRepository {
+	return &PGRepository{db: db}
+}
+
+func (r *PGRepository) Write(ctx context.Context, entry Entry) error {
+	const query = `
+		insert into audit_logs (id, actor_user_id, entity_type, entity_id, event_type, status, message, metadata)
+		values ($1, $2, $3, $4, $5, $6, $7, $8::jsonb)
+	`
+
+	_, err := r.db.Exec(
+		ctx,
+		query,
+		uuid.New(),
+		entry.ActorUserID,
+		entry.EntityType,
+		entry.EntityID,
+		entry.EventType,
+		entry.Status,
+		entry.Message,
+		MarshalMetadata(entry.Metadata),
+	)
+	return err
+}
+
+func (r *PGRepository) List(ctx context.Context, limit int) ([]map[string]any, error) {
+	rows, err := r.db.Query(ctx, `
+		select id, event_type, entity_type, status, message, created_at
+		from audit_logs
+		order by created_at desc
+		limit $1
+	`, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var entries []map[string]any
+	for rows.Next() {
+		var id uuid.UUID
+		var eventType, entityType, status, message string
+		var createdAt any
+		if err := rows.Scan(&id, &eventType, &entityType, &status, &message, &createdAt); err != nil {
+			return nil, err
+		}
+		entries = append(entries, map[string]any{
+			"id":          id,
+			"event_type":  eventType,
+			"entity_type": entityType,
+			"status":      status,
+			"message":     message,
+			"created_at":  createdAt,
+		})
+	}
+
+	return entries, rows.Err()
+}