[12] TCP105 totem board emulator and screen

[jvwaldrich0]

Task 12 of 16 — these are sequential, do them in order.

Previous: #14 · Next: #16

Port target: cloudpark-toolkit (Go) → this repo (Rust). Reference paths below are relative to that repo.

Goal

The TCP105 totem-board emulator (server) and its TUI screen.

Scope

Server (src/tcp105.rs), on :8008 by default (--listen to bind a specific loopback so a real cloudpark-hw can share the machine):

• The HW dials a fresh connection per command — answer exactly one command per accepted connection.
• Handle: reset, version info, CPU unique code, config update, relay control (track relay state), voice broadcast (task 11), get IO status, RFID.
• SerialTransfer reassembly: buffer the stream (cap at 4 MiB against a bogus length prefix) and hand Serial2 payloads to the ticket renderer (task 10).
• Digital input toggles: the TUI flips inputs 1–5, the server pushes UploadIOStatus to the HW upload address — auto-learned from the incoming connection unless --hw-addr is set.

Screen:

• Menu: Get info / Inputs & relays.
• Get info: listen address, HW upload address, tickets saved, last command.
• Inputs & relays: cursor over inputs 1–5 (loop detector, pick-card, help), space toggles; relay state shown live.

Reference

cloudpark-toolkit/internal/tcp105/server.go (406) + server_test.go (253), internal/tui/tcp105.go

Done when

• Test: a fake HW client gets a correct reply for each opcode.
• Toggling an input in the TUI produces an UploadIOStatus frame with the right bit set.
• A ticket pushed over Serial2 lands in the ticket dir as a PDF.