v0.13.1 folder restructure, test script added, format adapter async fix

internal/core/flow.go

@@ -0,0 +1,27 @@
+package core
+
+import (
+	"encoding/json"
+	"time"
+)
+
+// LogEntry represents a single log record flowing through the pipeline
+type LogEntry struct {
+	Time    time.Time       `json:"time"`
+	Node    string          `json:"node,omitempty"` // origin node identity for chained topologies; first hop stamps, relays preserve
+	Source  string          `json:"source"`
+	Level   string          `json:"level,omitempty"`
+	Message string          `json:"message"`
+	Fields  json.RawMessage `json:"fields,omitempty"`
+	RawSize int64           `json:"-"`
+}
+
+// TransportEvent contains the final payload and minimal metadata needed by sinks
+type TransportEvent struct {
+	Time time.Time
+	// Formatted, serialized log payload
+	Payload []byte
+	// Structured entry for re-serializing sinks (chain links). Zero Time => absent
+	Entry LogEntry
+}
+