feat(tests): add fuzz testing for packet unpacking functionality

pkg/packet/packet_fuzz_test.go

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: 0BSD
+// Copyright (c) 2024-2026 Sudo-Ivan / Quad4.io
+package packet
+
+import (
+	"testing"
+)
+
+func FuzzPacketUnpack(f *testing.F) {
+	// Add some valid packets as seeds
+	p1 := &Packet{
+		HeaderType:      HeaderType1,
+		PacketType:      PacketTypeData,
+		DestinationType: 0x01,
+		DestinationHash: make([]byte, 16),
+		Context:         ContextNone,
+		Data:            []byte("hello"),
+	}
+	if err := p1.Pack(); err == nil {
+		f.Add(p1.Raw)
+	}
+
+	p2 := &Packet{
+		HeaderType:      HeaderType2,
+		PacketType:      PacketTypeAnnounce,
+		TransportID:     make([]byte, 16),
+		DestinationHash: make([]byte, 16),
+		Context:         ContextNone,
+		Data:            []byte("announce"),
+	}
+	if err := p2.Pack(); err == nil {
+		f.Add(p2.Raw)
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		p := &Packet{Raw: data}
+		// We don't care about the error, just that it doesn't panic
+		_ = p.Unpack()
+	})
+}
+