Add supporting infrastructure for nginx HTTP capture using kretprobe
on __x64_sys_recvfrom to replace the blocked tracepoint sys_exit_recvfrom.
Changes:
- bpf/bpf_types.h: Add nginx_pid_map for filtering recvfrom by PID
- cmd/ja4ebpf/main.go: Add Uprobes configuration section
- Makefile: Add test targets for recvfrom validation
- internal/loader: Generate nginx HTTP event structures
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
382683710a