Wires the SECS-I Protocol FSM behind an asio TCP socket so the block
protocol can run over loopback without serial hardware. Mirrors
secsgem-py's `secsitcp/` adapter — useful for back-to-back simulators
and CI without a serial device.
Adds:
include/secsgem/secsi/tcp_transport.hpp
src/secsi/tcp_transport.cpp
tests/test_secsi_tcp.cpp
The transport:
- Splits outgoing SECS-II messages into blocks (transparent multi-block).
- Accumulates incoming blocks until end_block=true, then assembles and
delivers as a single SECS-II message — same surface as the HSMS
Connection's MessageHandler.
- Drives T1 / T2 timers from asio steady_timer; T3/T4 stay upper-layer
per the FSM contract.
- Auto-allocates monotonic system bytes per send.
Tests cover single-block delivery, multi-block reassembly (700-byte
ASCII body spanning multiple SECS-I blocks), and bidirectional exchange.
This closes Tranche A (catch-up to secsgem-py wire/transport surface).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
