Initial commit: wireframe packet capture/analysis tool

Terminal packet capture and analysis tool built to learn the C++
memory model (byte layout, alignment, endianness, std::span over
unowned buffers) via a real capture pipeline.

- Hand-rolled L2-L4 decoders (Ethernet, IPv4, IPv6 with extension
  header walking, TCP, UDP) over std::span, no struct-casting
- L7 dissector interface with DNS, HTTP, and TLS SNI implementations
- pcapng read/write for Wireshark-compatible capture files
- Bounded capture queue: drop-on-backpressure for live capture,
  blocking push for faithful file replay
- Kernel-level BPF filtering (-f) and a separate display-only search
  (-g / interactive) that doesn't touch what's captured
- Replay mode (-r) reads a saved pcapng file back through the same
  pipeline as live capture, no root or live device needed
- pcap_stats() surfaces kernel/interface drops invisible to the
  capture queue's own counter
- Three frontends sharing one CaptureSession setup path: CLI, TUI
  (FTXUI, primary), GUI (Dear ImGui + SDL3, secondary)
- 89 unit tests (doctest) plus 9 libFuzzer harnesses covering every
  hand-rolled parser; fuzzing found and fixed a real OOM in the
  pcapng reader (unbounded allocation from an untrusted length field)

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/test_byteio.cpp b/tests/test_byteio.cpp
new file mode 100644
index 0000000..81fa741
--- /dev/null
+++ b/tests/test_byteio.cpp
@@ -0,0 +1,23 @@
+#include <doctest/doctest.h>
+
+#include <vector>
+
+#include "wireframe/byteio.hpp"
+
+using namespace wireframe;
+
+TEST_CASE("read_be16 reads a big-endian 16-bit value") {
+    std::vector<unsigned char> bytes = {0x12, 0x34};
+    CHECK(read_be16(bytes, 0) == 0x1234);
+}
+
+TEST_CASE("read_be32 reads a big-endian 32-bit value") {
+    std::vector<unsigned char> bytes = {0xDE, 0xAD, 0xBE, 0xEF};
+    CHECK(read_be32(bytes, 0) == 0xDEADBEEFu);
+}
+
+TEST_CASE("read_be16/read_be32 read from a nonzero offset") {
+    std::vector<unsigned char> bytes = {0x00, 0x00, 0x12, 0x34, 0x56, 0x78};
+    CHECK(read_be16(bytes, 2) == 0x1234);
+    CHECK(read_be32(bytes, 2) == 0x12345678u);
+}