docs: the TCPStreamer source kind, the client's TCP mode, and its probes

docs/claude/build-and-run.md

@@ -164,6 +164,16 @@ python3 tools/mock_flatudp.py --port 44588 --rate 1000 --signals 'Trigger:uint8,
 (Quote the `signals` value: zsh globs the `[4]`. The mock takes the same text with or without the trailing `w`;
 the datagram is the same, `w` only says how the app shows it.)
 
+`--source tcps` receives a MARTe2 `TCPStreamer` (standalone) or `TCPStreamService` (named stream) over
+TCP: `server` (default 127.0.0.1), `port` 44500, and `stream` (optional; a `SUBSCRIBE` frame is sent only when it is
+set). `tools/mock_tcpstreamer.py` serves one client with the `mock_udpstreamer.py` signals (`--port`, `--stream`
+to require a `SUBSCRIBE`, `--rate`, `--batch`, `--freq`, `--close-after S`, `--drop-every N`).
+
+```sh
+python3 tools/mock_tcpstreamer.py --port 44500 --stream fast &
+./build/udpscope --source tcps --source-opt port=44500 --source-opt stream=fast
+```
+
 `tools/mock_udpstreamer.py` has waveform-injection options used by the probes:
 
 - `--square-harmonics N` shapes `square`: `N` odd harmonics of the ideal step's Fourier
@@ -201,7 +211,8 @@ form for a new host. Every probe below passes `--server`, so none of them sees i
 
 `deps/plotter` is built from source with only the GTK4 adapter enabled
 (`PLOT_BUILD_GTK4`); its tests and examples are forced off. `deps/udpsclient` is a
-vendored C99 source pair compiled into a static lib. `deps/udpsclient` gained one
+vendored C99 source pair compiled into a static lib. `deps/udpsclient` gained a TCP
+transport mode (item 6 below) and one
 additive entry point for the packet capture — `udps_client_set_datagram_cb()`, firing
 inside `udps_client_poll()` immediately after the UDP `recv()` returns, before the
 magic check or reassembly — plus the public `UDPS_MAX_DATAGRAM_BYTES` the capture
@@ -227,7 +238,7 @@ handler clears either pointer without knowing which dialog it is. Presenting eit
 app's plain `GtkApplicationWindow` is supported and warning-free; it was checked.
 
 `deps/udpsclient` is a vendored C99 source pair and its diff from the upstream source
-is intentional. Five things were changed:
+is intentional. Six things were changed:
 
 1. **A reorder ring of reassembled payloads.** When a packet arrives with a higher counter
    than expected, the raw datagram is held in a fixed-size ring rather than decoded immediately.
@@ -258,6 +269,15 @@ is intentional. Five things were changed:
    would be the same silent loss by another route. `stats.reorder_overflows` counts the event,
    so an undersized ring is a reading rather than a mystery; it is surfaced in the exit dump and
    the `[reseq-probe]` line as `overflows=`.
+6. **A TCP transport mode.** `udps_client_config_t::use_tcp` / `stream_name` select a TCP
+   connection to a MARTe2 `TCPStreamer` or `TCPStreamService`: `connect_tcp()` (a 3 s connect
+   bound through `SO_SNDTIMEO`, a 1 s receive bound, an optional `SUBSCRIBE` frame,
+   `UDPS_PKT_SUBSCRIBE = 5`, sent only when `stream_name` is set), the existing
+   `read_tcp_frame()` for the frames, the reorder window forced to 0 (TCP is ordered, so a
+   counter gap is a server-side drop and is reported at once), multicast forced off, no
+   DISCONNECT frame on close (a write to a closed peer would raise SIGPIPE), no keepalive ACK
+   and no datagram tap. A frame must fit `UDPS_MAX_DATAGRAM_BYTES` (the server's
+   `MaxPayloadSize` default of 60000 does). A stream name over 255 bytes is refused at create.
 
 `deps/plotter` is upstream's own repository and this app's figure support was added
 there rather than worked around here: `Figure::set_min_y_gutter()` (a floor under the