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, 18 insertions, 0 deletions

diff --git a/fuzz/fuzz_summarize.cpp b/fuzz/fuzz_summarize.cpp
new file mode 100644
index 0000000..c1872fd
--- /dev/null
+++ b/fuzz/fuzz_summarize.cpp
@@ -0,0 +1,18 @@
+#include <cstddef>
+#include <cstdint>
+#include <pcap.h>
+
+#include "wireframe/summarize.hpp"
+
+// Fuzzes the full decode chain together (Ethernet/RAW -> IPv4/IPv6 ->
+// TCP/UDP -> L7), not just each layer in isolation - catches bugs
+// that only show up from one layer's output feeding the next (e.g. a
+// span that's technically valid per-layer but wrong at the boundary).
+// The first byte selects which datalink summarize_packet() should
+// assume; the rest is the packet itself.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    if (size < 1) return 0;
+    int datalink = (data[0] % 2 == 0) ? DLT_EN10MB : DLT_RAW;
+    wireframe::summarize_packet({data + 1, size - 1}, datalink);
+    return 0;
+}