Port envd from e2b with internalized shared packages and Connect RPC

- Copy envd source from e2b-dev/infra, internalize shared dependencies
  into envd/internal/shared/ (keys, filesystem, id, smap, utils)
- Switch from gRPC to Connect RPC for all envd services
- Update module paths to git.omukk.dev/wrenn/{sandbox,sandbox/envd}
- Add proto specs (process, filesystem) with buf-based code generation
- Implement full envd: process exec, filesystem ops, port forwarding,
  cgroup management, MMDS integration, and HTTP API
- Update main module dependencies (firecracker SDK, pgx, goose, etc.)
- Remove placeholder .gitkeep files replaced by real implementations

envd/internal/logs/bufferedEvents.go

@@ -0,0 +1,47 @@
+package logs
+
+import (
+	"time"
+
+	"github.com/rs/zerolog"
+)
+
+const (
+	defaultMaxBufferSize = 2 << 15
+	defaultTimeout       = 2 * time.Second
+)
+
+func LogBufferedDataEvents(dataCh <-chan []byte, logger *zerolog.Logger, eventType string) {
+	timer := time.NewTicker(defaultTimeout)
+	defer timer.Stop()
+
+	var buffer []byte
+	defer func() {
+		if len(buffer) > 0 {
+			logger.Info().Str(eventType, string(buffer)).Msg("Streaming process event (flush)")
+		}
+	}()
+
+	for {
+		select {
+		case <-timer.C:
+			if len(buffer) > 0 {
+				logger.Info().Str(eventType, string(buffer)).Msg("Streaming process event")
+				buffer = nil
+			}
+		case data, ok := <-dataCh:
+			if !ok {
+				return
+			}
+
+			buffer = append(buffer, data...)
+
+			if len(buffer) >= defaultMaxBufferSize {
+				logger.Info().Str(eventType, string(buffer)).Msg("Streaming process event")
+				buffer = nil
+
+				continue
+			}
+		}
+	}
+}