fresnel-fourier campaign scaffold: peer to libva-multiplanar, RK3399 target

Roll out libva-v4l2-request-fourier on fresnel (Pinebook Pro / RK3399)
with broader codec scope than ohm-side libva-multiplanar:

- H.264 + HEVC + VP9 via the rkvdec block (/dev/video3)
- MPEG-2 + VP8 via the hantro-vpu-dec block (/dev/video5)

Topology: peer campaign, independent 8(+1) loop. fresnel-fourier
results do not gate libva-multiplanar Phase 8 closes. Code-side work
in the shared fork (../libva-multiplanar/libva-v4l2-request-fourier/)
lands per Phase 2 source-read of each iteration.

Phase 0 task 1: recover fresnel from the SDDM greeter crash-loop
(per ~/.claude/plans/dynamic-forging-piglet.md). Recovery is bookkept
inside this campaign's Phase 0, not as an out-of-band prereq.

Verified 2026-05-07 via SSH:
- linux-eos-arm 6.19.9-99 has CONFIG_FTRACE=y + CONFIG_FUNCTION_TRACER=y
  + CONFIG_DYNAMIC_FTRACE=y + CONFIG_TRACING=y. /sys/kernel/tracing/
  populated. No kernel rebuild needed for trace work.
- /dev/video3 = rkvdec (NV12 capture, MPLANE).
- /dev/video5 = hantro-vpu, card type rockchip,rk3399-vpu-dec.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,5 @@
+references/
+phase*_evidence/
+*.log
+*.pcap
+*.strace