e1608: probe and docs for the network scan

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

docs/claude/verification.md

@@ -441,6 +441,13 @@ precedent, not an exception.
   - **a rejected code:** mock `--code 1234`, app `code=7`: one error line, the retries stop.
 - `UDPSCOPE_PROBE_E1608_RECONNECT=8000` -- reads the source after the mock dropped the link and 500 ms
   later checks the frame count moved on. The reading's own entry is in `probe-readings.md`.
+- `UDPSCOPE_PROBE_E1608_SCAN=1000` with `UDPSCOPE_EXIT_AFTER_MS=6500`, run as `--source e1608 --source-opt
+  address=127.0.0.1` against `tools/mock_e1608.py` on its default port 54211 (the form scans that port) -- builds
+  the connection form, presses **Scan network**, expects the mock to be listed, clicks the result (address
+  filled, MAC and subnet cleared), presses **Use MAC** (MAC filled, the others cleared), scans again and checks
+  the results were replaced. `UDPSCOPE_PROBE_E1608_SCAN_MAC` names another board (a real one) instead of the
+  mock's `00:80:2f:00:16:08`. One `[e1608] scan:` line. It needs a non-loopback up interface with a broadcast
+  address; when the board did not answer a second line says so, and the run proves nothing about the scan.
 - `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 and the connect form's validity rules and signal-row editor (both
   need no source; it covers the `w` suffix, the waveform and 256-channel rules, the channel decode and the