POG-EDGE WiFi bench — Pos5 ↔ Pos4 (DT-2670-18-5)
=================================================

Configured 2026-07-19. PSK lives only in /etc/fixture/edge.env on the Pis
(not in this file / not in git).

NOTE (2026-07-20): shielded copper pos5↔pos4 is permanently gone. This hop stays
WireGuard+gretap forever. Teardown below must NOT re-plug copper. For phone
hotspot / LTE hairpin, see LTE_HAIRPIN_BENCH.txt.

Topology (corrected)
--------------------
- Pos5 is end-of-bank: NO local eth game leg. Copper to pos4 is replaced by WG.
  EDGE_GAME_IF= (empty) → bridge ETH_PORTS = gretap only (tunnel-only).
- Pos4 keeps eth1 toward the bank / local T340; wlan0 is WG transport.
  EDGE_GAME_IF=eth1 → ETH_PORTS = eth1,gretap.

State after agent prep
----------------------
- EDGE_MODE=1, EDGE_UPLINK=wlan0 on both
- SSID DT-2670-18-5 joined on both
- Pos5 wlan0 = 10.1.10.140  (EDGE_ROLE=office, GAME_IF empty)
- Pos4 wlan0 = 10.1.10.39   (EDGE_ROLE=pos4, GAME_IF=eth1)
- /etc/wireguard/wg0.conf Endpoints point at peer WLAN IPs :51820
- WireGuard handshake verified; active gretap is gretap1 (gretap0@NONE stuck —
  reboot clears; run_bridge_edge_bench reads .active_gretap)

Physical
--------
- Unplug copper between pos4 ↔ pos5 (tunnel replaces that hop).
- Pos5: no eth cables required (wlan only).
- Pos4: eth1 stays on local game / chain toward pos3.
- fixture-prod stays disabled on these bench seats.

Start bridges (YOU — Pi UI console, foreground)
-----------------------------------------------
Preferred (all knobs in env — role / EDGE_MODE / FIXTURE_POS / CHANNEL /
FIXTURE_PROD). Same command on every seat:

  cd ~/EtherGold/dev && bash run_ethergold.sh

EDGE seats auto-elevate with sudo -E. Expect:
  Pos5: eth_ports=gretap1 (or gretap0) — no eth1
  Pos4: eth_ports=eth1,gretap1

Legacy launchers still work and redirect into run_ethergold when EDGE_MODE=1.

Folders (easy to mix up after update.sh)
---------------------------------------
While WiFi edge soak is up, pos4 and pos5 use EDGE (EDGE_MODE=1). Prefer
``run_ethergold.sh`` from ``~/EtherGold/dev`` so copper launchers cannot
silently drop gretap. Do not prefix CLI env — it is already on the Pi.

  Any seat:  cd ~/EtherGold/dev && bash run_ethergold.sh

Do NOT force EDGE_MODE=0 on pos4 while the peer is tunnel-only — that blacks
out pos5. Copper launchers redirect to run_ethergold when EDGE_MODE=1.

Pass checks
-----------
  sudo wg show          # latest handshake, transfer climbing
  ip -br link | grep gretap
  Pos4 games talk to pos5 side across the missing copper hop

Teardown (stop tunnel — copper stays out)
-----------------------------------------
1. Ctrl-C both foreground bridges.
2. On each Pi:
     cd ~/EtherGold/dev/pog-edge
     sudo bash tunnel_down.sh
3. Leave EDGE_MODE=1 for this hop (copper will not return).
4. Do NOT re-plug copper pos4 ↔ pos5.
5. Stuck gretap0@NONE: reboot that Pi when convenient.