Record the on-air verification and how to run the bench beacon

Both firmware fixes are now confirmed over the air, with the sniffer board
capturing and asn1tools judging the result.

GN lifetime: our station transmits 0x05 (1 s), the value both bench stations
use, where the August captures show 0x83 (3200 s) for the same frames. 397 CAMs
from station 999999 decode and re-encode byte-identically, so the whole
transmit chain is right on the wire, not only in the host tests.

yawRateConfidence: the bench beacon, flashed to a spare board, sends CAMs that
decode and re-encode byte-identically as well (72 of 72 from station
0x0BADC0DE). NOTES.md now says how to flash that beacon and how to check what
it sends, including that it shares the phone pinger's MAC and the two are told
apart by station ID.

The new firmware also runs on the OBU with the phone attached: CAM, DENM and
SPATEM from the bench stations all keep decoding in the app now that messages
are cut to the length their header declares.

Signed reception stays open. The CiT One transmits unsigned and nothing else
here signs, so it needs real roadside traffic, the CiT One switched to signed
mode, or a replay firmware on a spare board.

Two bench facts worth not rediscovering are recorded too: opening COM3's
console resets the OBU and drops the phone's USB link, and every capture taken
before today is truncated at its first corrupted record, because the receiver's
console inserts a CR before every 0x0a byte of the binary pcap stream.
live_capture.py now undoes that, a change that lives in the receiver repo and
is not part of this commit.

TODO.md

@@ -9,20 +9,24 @@ Engineering to-do list. The reviewer-facing open items live in
 
 `geonet.c` now writes GN lifetime `0x05` (1 s) instead of `0x83`, which decoded to 3200 s. Changed
 in both `obu-firmware` and `obu-cam-transmistter`. Both still build (IDF 6.1 / 5.5.4), and the
-compiled `geonet_wrap_shb` stores the new byte, but it has not been seen on air yet. Nothing else
+compiled `geonet_wrap_shb` stores the new byte. Confirmed on air 2026-09-14. Nothing else
 reads this byte (`gn_unwrap.c` ignores it, the app never sees GN headers), so the app does not
 need updating alongside the firmware.
 
 Needs: the phone with the app, the OBU ESP32-C5, and a **second** ESP32-C5 running
 `its-g5-receiver-firmware` to capture with.
 
-- [ ] Flash `obu-firmware` (see `obu-firmware/FLASHING.md`).
-- [ ] Connect the phone, let it send CAMs, and confirm the CAM Pinger's `tx fail` counter stays 0.
-- [ ] Capture with the receiver into `its-g5-receiver-firmware/recordings/`.
-- [ ] Run `python obu-firmware/test/pcap_gn_tally.py its-g5-receiver-firmware/recordings/<capture>.pcap`.
-      The rows for the phone's pseudonym MACs must show SHB, port 2001, lifetime `0x05`, exactly
-      like every other station's CAMs.
-- [ ] While the phone is connected: real-station CAMs/DENMs still reach the app (RX path unchanged).
+- [x] Flash `obu-firmware` (done 2026-09-14 on COM3; flash backed up first to
+      `Documents/micrOBU_workspace/firmware-backups/COM3-2026-09-14-before-secured-rx.bin`).
+- [x] Capture with the receiver (COM8) into `its-g5-receiver-firmware/recordings/`.
+- [x] `pcap_gn_tally.py` on capture_20260914_132126.pcap: our station sends SHB, port 2001,
+      lifetime `0x05`, same as both bench stations. It was `0x83` in the August captures.
+- [x] Real-station CAMs/DENMs/SPATEM still reach the app (logcat: `handleCamUper`,
+      `handleDenmUper`, `handleSpatUper` all decoding, 2026-09-14).
+- [x] Our own CAMs decode on air: 397 frames from station 999999 decode with asn1tools and
+      re-encode byte-identically.
+- [ ] Confirm the CAM Pinger card's `tx fail` / oversize / CRC counters are 0 (needs a look at the
+      phone; not readable from the PC).
 
 Partial check possible with one board and no phone: flash it, `idf.py -p COMx monitor`, and look
 for `OCB @ 5900 MHz - TX/RX armed`. That proves the new build boots and brings the radio up, not
@@ -33,11 +37,12 @@ that it transmits correctly.
 Its `cam.c` (compiled into that firmware) wrote `yawRateConfidence` as 3 bits / 7 instead of
 4 bits / unavailable(8), the bug the app fixed on 2026-08-20. Fixed in it and in obu-firmware's
 reference copy; asn1tools now decodes the CAM and re-encodes it byte-identically, and it builds on
-IDF 5.5.4. No board runs this firmware right now (the production OBU runs obu-firmware), so this
-only matters if it is flashed again:
+IDF 5.5.4. Since 2026-09-14 the spare board on COM10 runs it as a bench beacon:
 
-- [ ] After flashing it: capture, run `pcap_gn_tally.py`, and decode the CAM payload with
-      asn1tools (`py -3.11`, modules in `asn1/`).
+- [x] Done 2026-09-14: flashed on COM10 and captured on COM8. All 72 CAMs from station
+      195936478 (0x0BADC0DE) decode with asn1tools and re-encode byte-identically, so the
+      4-bit yawRateConfidence is right on air. COM10 now runs this beacon rather than
+      obu-firmware - reflash it if the spare is needed as an OBU again.
 
 ### Signed-message reception and exact payloads (added 2026-09-11)
 
@@ -45,17 +50,21 @@ obu-firmware's `gn_unwrap.c` now unwraps TS 103 097 signed packets (signature no
 reported as V2X_RX flags bit1) and cuts every message to the length its header declares, dropping
 the 8 bytes the chip's RX appends to each frame, which were forwarded to the phone until now.
 Verified on the host (`obu-firmware/test/host`: chain, replay of all recordings against asn1tools,
-50M-iteration fuzz) and built on IDF 6.1, but not flashed: the production OBU still runs the
-2026-09-10 build. Needs the OBU with this build, the phone, and signed traffic - real vehicles or
+50M-iteration fuzz) and flashed to the production OBU on 2026-09-14. The remaining gap is signed
+traffic to receive: real vehicles or
 RSUs, since the bench CiT One sends unsigned. A second ESP32 running the receiver firmware is
 optional, but shows what was on air at the time.
 
-- [ ] Flash obu-firmware (this also carries the GN lifetime fix above).
+- [x] Flash obu-firmware (done 2026-09-14, COM3).
+- [x] Unsigned bench traffic still decodes in the app, with messages now cut to their declared
+      length (CAM, DENM and SPATEM all decoding in logcat after the flash).
 - [ ] Near signed traffic: signed CAMs/DENMs appear in the app, and a simultaneous capture shows
-      them on air (`pcap_gn_tally.py` lists them as `secured`).
-- [ ] Unsigned bench traffic still decodes in the app as before (messages now arrive 8 bytes
-      shorter).
-- [ ] The heartbeat's oversize counter still counts over-long messages (e.g. road SPATEMs).
+      them on air (`pcap_gn_tally.py` lists them as `secured`). NOT possible at this bench: the
+      CiT One transmits unsigned (`ItsGnSecurity = 0`) and nothing else here signs. Needs a drive
+      past real RSUs, the CiT One switched to signed mode if its API allows, or a replay firmware
+      on a spare board that re-transmits the recorded signed frames.
+- [ ] The heartbeat's oversize counter still counts over-long messages. Not exercised at the
+      bench: the SPATEMs here are ~340 bytes on air, far below the cap.
 
 ## Set up host testing
 
@@ -92,6 +101,19 @@ Suggested order after the host tests exist:
 Dropped: building vanetza as a GN/BTP oracle. Real captures (`pcap_gn_tally.py`), the host
 round-trip test and `asn1tools` for UPER cover what it would have checked.
 
+## Follow-ups found 2026-09-14
+
+- [ ] **Commit the `live_capture.py` fix in the receiver repo.** Its console inserts a CR before
+      every LF, which also hits every 0x0a byte of the binary pcap stream, shifting pcap record
+      headers and frames. A 787 KB capture parsed cleanly for only 82 of ~2000 records, and DENMs
+      showed up on nonsense BTP ports. `undo_crlf()` now reverses it on the raw stream before
+      framing; afterwards a capture parsed to EOF and DENMs read as port 2002. This is the
+      "occasional byte inserted mid-frame" in the older recordings, so **every capture taken before
+      2026-09-14 is truncated at its first corrupted record** - re-measure anything derived from
+      them. The change is in the `its-g5-receiver-firmware` repo, uncommitted.
+- [ ] **Do not open COM3's console while the phone is attached.** Opening it toggles DTR/RTS on the
+      CH343 and resets the OBU, which drops the phone's USB link and needs a manual Connect.
+
 ## Follow-ups found 2026-09-11
 
 - [ ] **App: show the signed flag.** `V2xRxFrame.parse` in `SerialFrame.kt` only reads bit0 of