e1608: probe and docs for the network scan

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

docs/claude/probe-readings.md

@@ -1859,11 +1859,12 @@ The UDPS run has no `source-` page in `side_stack`, because the UDPS kind has no
 [e1608] scan socket closed by the board
 [e1608] reconnect: connects=2 connected=1 ok=1
 [e1608] resumed: frames_before=612 frames_after=662 ok=1
+[e1608] scan: found=1 ip=172.21.121.113 mac=00:80:2f:00:16:08 status='1 board found' fill_addr=1 fill_mac=1 rescan_replaced=1 ok=1
 ```
 
 `UDPSCOPE_PROBE_E1608=1500` (the first eight lines; `frames=` and the exact mean vary) and
-`UDPSCOPE_PROBE_E1608_RECONNECT=8000` (the last two) run as `--source e1608` against `tools/mock_e1608.py`
-with the options in `verification.md`. The line between `decode` and `reconnect` is the source's own stderr message
+`UDPSCOPE_PROBE_E1608_RECONNECT=8000` (the next two) run as `--source e1608` against `tools/mock_e1608.py`
+with the options in `verification.md`; `UDPSCOPE_PROBE_E1608_SCAN=1000` (the `scan` line) is a run of its own. The line between `decode` and `reconnect` is the source's own stderr message
 about the drop, not a probe line (its text is the error the source met, once per distinct message). `connected=0` throughout, with
 `actions: skipped (not connected)`, is the no-board run; it is a reading and not a failure, and it also prints
 the one `[e1608] handshake with ...: Connection refused` line, `stream: ... signals=0 expect=1 ... ok=0`,
@@ -1894,6 +1895,16 @@ the one `[e1608] handshake with ...: Connection refused` line, `stream: ... sign
   drop (neither the scan read nor the status check raised it), `resumed: ok=0` is a reconnect that did not restart
   the scan (it also reads 0 when `connects` is still 1, since a frame count that grows on a link that never dropped
   proves nothing).
+- `scan: found=1 ... ok=1`: the form's **Scan network** row against the mock. `found` is the result rows after
+  the first scan; `0` with the second line `did not answer` is an environment with no up, non-loopback
+  broadcast interface that reaches the mock (or a refused broadcast), **not a pass**. `ip` is the listed address
+  of the expected board and `mac` the MAC the probe looked for.
+- `status='1 board found'`: the row's subtitle at the end of the first scan (`N boards found` with more
+  than one). `No board found` with a mock running is the probe's sockets not reaching it.
+- `fill_addr=0`: a click on a result did not set only the address (the MAC or subnet kept a stale value), or it
+  told the dialog something other than once. `fill_mac=0`: the same for **Use MAC**.
+- `rescan_replaced=0`: the results of the first scan were kept or doubled by the second, so `start_scan` did not
+  remove them.
 
 ## `[flatudp]`