flatudp: vector rows as channels or as a waveform, a re-openable source, probes for both

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/claude/verification.md

@@ -443,22 +443,28 @@ precedent, not an exception.
   later checks the frame count moved on. The reading's own entry is in `probe-readings.md`.
 - `UDPSCOPE_PROBE_FLATUDP=2500` with `UDPSCOPE_EXIT_AFTER_MS`, run as `--source flatudp` against
   `tools/mock_flatudp.py` -- the flat UDP source end to end: a hand-computed codec and decode check (it
-  needs no source), the stream's signal names and declared rate, the channel count (one per signal), value
-  continuity across the first two signals (all-scalar lists only), the wrong-size accounting and the capture
-  button. It enables the signals itself, so do **not** add `UDPSCOPE_ENABLE_ALL_MS`. Runs, each short and
-  serial, with the mock killed afterwards (quote the `signals` value: zsh globs the `[4]`):
-  - **mixed list, gap and bad datagrams:** mock `--rate 1000 --signals Trigger:uint8,Ia:float32,Cnt:uint64,Wave:int16[4]
-    --gap 9,5 --bad-every 1 --log /tmp/flatudp-mock.log` started 1 s before the app, the same `signals` as a
-    `--source-opt`, with `UDPSCOPE_PROBE_FLATUDP=2500 UDPSCOPE_PROBE_FLATUDP_GAP=8000 UDPSCOPE_EXIT_AFTER_MS=14500`;
-    stderr carries exactly one `datagram of 22 bytes, expected 21` line. The mock's clock starts about 4 s
-    before the app's probe clock (`xvfb-run` and the app's own startup), so a gap of 9 s to 14 s on the mock's
-    clock covers the app's 8 s probe (silence) and ends before its 12 s one (resumed); a mock gap measured in
-    the app's own seconds would miss both;
-  - **scalar list, big endian (batching, continuity):** mock `--signals Trigger:uint8,Ia:float32,Cnt:uint64 --big-endian`,
-    app `--source-opt endian=big`, `UDPSCOPE_PROBE_FLATUDP=2500 UDPSCOPE_EXIT_AFTER_MS=5000`;
+  needs no source; it covers the `w` suffix, the waveform and 256-channel rules, the channel decode and the
+  float64/uint16/int32/uint32/int64 types in both byte orders), the stream's channel names (`Wave[0]`..
+  for a `channels` vector) and declared rates (`rate * count` for a waveform), the channel count, value
+  continuity per row (and the offset between a vector's elements, or a waveform's block phase), the
+  wrong-size accounting and the capture button. It enables the signals itself, so do **not** add
+  `UDPSCOPE_ENABLE_ALL_MS`. Runs, each short and serial, with the mock killed afterwards (quote the `signals`
+  value: zsh globs the `[4]`):
+  - **mixed list, gap and bad datagrams:** mock `--rate 1000 --signals 'Trigger:uint8,Ia:float32,Cnt:uint64,Wave:int16[4]'
+    --gap 8,4 --bad-every 1` started 1 s before the app, the same `signals` as a `--source-opt`, with
+    `UDPSCOPE_PROBE_FLATUDP=2500 UDPSCOPE_PROBE_FLATUDP_GAP=1500 UDPSCOPE_EXIT_AFTER_MS=14500`; stderr carries
+    exactly one `datagram of 22 bytes, expected 21` line. The silence probe is a 100 ms poll that waits for the
+    stream, then for the 2 s of silence to take the source down, then for it to come back, so it does not
+    depend on when `xvfb-run` finished starting; the only requirement is that the mock's gap begins after
+    the app connected (the mock's clock starts about 4 s before the app's) and ends in time to read the return
+    (`--gap 8,4` with a 14.5 s run does both with several seconds of margin);
+  - **waveform-only list:** mock `--signals 'Wave:int16[4]w'`, app `--source-opt 'signals=Wave:int16[4]w'`,
+    `UDPSCOPE_PROBE_FLATUDP=2500 UDPSCOPE_EXIT_AFTER_MS=5000`: one channel at `rate=4000`;
+  - **big endian (decode of every width through the stream):** mock `--big-endian` on the mixed list, app
+    `--source-opt endian=big`, `UDPSCOPE_PROBE_FLATUDP=2500 UDPSCOPE_EXIT_AFTER_MS=5000`;
   - **no sender:** `connected=0` throughout, a reading and not a failure.
-- `UDPSCOPE_PROBE_FLATUDP_GAP=8000` -- reads the source inside the mock's silence (2 s after its last datagram
-  the source is disconnected) and 4 s later checks it reconnected and the stream moved on.
+- `UDPSCOPE_PROBE_FLATUDP_GAP=1500` -- starts the silence poll described above (2 s after the source's last
+  datagram it must be disconnected; then it must reconnect and the frame count move on).
 - `UDPSCOPE_PROBE_SEARCH_MS` — runs a buffer search for the armed condition, cross-checks the live
   trigger's own `t0` against the nearest hit (`agree=1` is the load-bearing reading), and jumps to
   hit 0. Reports the resulting `mode=`, `axis=` and `marks placed=`.