Drop goals and open-questions docs, cut PTP from the appliance kernel

docs/README.md

@@ -2,14 +2,14 @@
 
 Project knowledge that moves and versions with the repo.
 
+cabletest finds Ethernet cables that misbehave under sustained full-duplex 10 Gbit load. It exchanges raw Ethernet frames (no IP, no ARP) across a variety of sizes and payloads between two directly-cabled ports on one host, and attributes every problem it can to the cable rather than the host. It runs as PID 1 on a dedicated appliance with a framebuffer UI; development happens on the same machine under Arch. The target of measurement is the cable, not throughput — line rate is a means to stress the physical layer.
+
 General:
 
-- [goals.md](goals.md) — what cabletest is for and what it must output.
-- [state.md](state.md) — where things are now: the box and what's in it, out-of-repo artifacts, every-boot steps. **All current-placement state lives here and only here.**
+- [state.md](state.md) — where things are now: the box and what's in it, the bench driver, every-boot steps. **All current-placement state lives here and only here.**
 - [hardware.md](hardware.md) — host rules: interface conventions, tuning, how to run.
 - [measurement.md](measurement.md) — how to measure correctly; performance results and dead ends.
 - [xdp.md](xdp.md) — the AF_XDP datapath experiment: what it proved, what rebuilding it needs, why it can't run on the X520.
-- [open-questions.md](open-questions.md) — the genuinely open problems, as pointers into the docs that hold their detail.
 
 Per-device (each directory: device doc + its datasheets):