Skill car-logs: fetch and read the car's recordings

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

.claude/skills/car-logs/SKILL.md

@@ -0,0 +1,69 @@
+---
+name: car-logs
+description: Download the signal recordings the MG4 sent to the car server (fetch-logs) and read them. Use when the owner says a recording is on the server, asks to get, download or look at the car's logs or recordings, or after a test drive with the signal recorder.
+---
+
+# Fetch and read the car's recordings
+
+The app's signal recorder (Logs tab, `SignalRecorder`) sends each finished recording to the
+car server (`LogOutbox`, `PUT /v1/logs/{name}`); the server keeps the newest 200
+(`server/logs.go`). `fetch-logs` in the dev shell downloads the ones not yet in `logs/`.
+
+## Fetch
+
+```sh
+nix develop -c fetch-logs
+```
+
+It prints each new file (`logs/signal-recording-YYYYMMDD-HHMMSS.txt`) and `fetch-logs: N new`.
+The token comes from `~/.config/nilsmg4/logs-token` (the server's `LOGS_TOKEN`) and goes only in
+a header.
+
+- **Never print, cat or echo the token**, and never pass it on a command line you show. Do not
+  read the token file.
+- `no token`: ask the owner to put the server's `LOGS_TOKEN` in `~/.config/nilsmg4/logs-token`
+  (and in `k8s/secrets/secrets.yaml`, then apply it). Do not create or fill it yourself.
+- HTTP 401: the file and the server's Secret differ. HTTP 404: reading is off (no
+  `LOGS_TOKEN` on the server) or the server is older than 2.9.0. The owner applies manifests and
+  Secrets; never run `kubectl` against the cluster, not even read-only.
+- `0 new`: nothing arrived. In the car, the Logs tab says "Sent to the server." or how many wait
+  and why (no server set up, server not reached, an HTTP status); the car retries every 2
+  minutes while the service runs.
+
+## Read
+
+The files are plain text but `file` may call them data; search with `rg -a`. Newest first:
+`ls -t logs/`. If the owner said what they did and when (e.g. "ACC on at 08:50, set speed
+100→90 at 08:51"), line those times up with the timeline.
+
+A recording has four parts, in this order:
+
+1. Header: captures, start time, app version.
+2. **Steering-wheel keys and notes.** The first note says whether listening worked:
+   `listening to N assistance properties (M refused)`, or `not possible (<reason>)`.
+3. **Assistance properties heard** (`EVHardware.listenToProperties` on `AssistBlock`, the
+   `0x21x0A1xx` block): change events, properties whose value changed first. This is where a
+   value shows up that the head unit fills only while someone listens.
+4. **Changed values (polled)**, rarest first, then **Everything, in order**: every capture
+   (about every 5 s) with what changed since the last.
+
+Useful cuts:
+
+```sh
+rg -a 'listening to' logs/<file>                                   # did listening work
+awk '/^Assistance properties heard/,/^$/' logs/<file>              # what listening heard
+rg -a 'A15B|A15A' logs/<file>                                      # one property's history
+rg -a 'getLatestSpeed' logs/<file> | head                          # the car's speed over time
+```
+
+Known leads (SPECS.md, 2026-10-27): `0x2160A15B` is `AAD_EPTCCTRGTSPD`, by its name the cruise
+control's target speed (0.0 when only polled); `0x2140A15A` moved between 3 and 7;
+`0x2160A1A3`/`0x2160A1A4` counted up by 0.1. A value that tracks what the owner did at the
+times they name is a lead; say how sure it is, and that it is not confirmed until a second
+drive shows the same.
+
+## Rules
+
+- Recordings are the car's data: `logs/` and `/signal-recording-*.txt` are gitignored. Never
+  commit, publish or upload them anywhere.
+- Findings that change what the project knows go into a `SPECS.md` done-log entry, as usual.

AGENTS.md

@@ -111,7 +111,7 @@ nix develop                                   # JDK 21, Android SDK, Go
 ./gradlew testStableDebugUnitTest testUnstableDebugUnitTest lintStableDebug
 build-car                                     # build/car/NilsMG4-unstable-<version>.apk + .sha256
 publish-car                                   # pre-release car-<version> on the forge (needs a token)
-fetch-logs                                    # the car's recordings from the server into logs/ (needs LOGS_TOKEN)
+fetch-logs                                    # the car's recordings from the server into logs/ (needs LOGS_TOKEN; skill car-logs)
 cd server && go vet ./... && go test ./... && govulncheck ./...
 ```
 

SPECS.md

@@ -140,6 +140,7 @@ tyre pressures, GPS (lat, lon, elevation, heading) and the is_* flags. It does *
   confirmed car facts, app structure, UI conventions, build/test/ship, documents. It replaces
   upstream's EVABRPUploader text. The test emulator is now in the flake: `nix run .#car-emulator`
   (Android 9 AOSP at 1920×720, 160 dpi; the car build installs as the system user — checked).
+- 2026-10-27 — Skill `car-logs` (`.claude/skills/car-logs/SKILL.md`; owner: "can we write a skill for downloading the logs?"): fetch with `fetch-logs` without ever showing the token, what its errors mean, how a recording is laid out, the cuts that find a lead, the leads so far, and that recordings are never committed. Its commands tried on the 08:52 recording.
 - 2026-10-27 — Server 2.9.0 pushed (`sha256:c68837f0e53cfca150644987be535e04d5e999bd4c91064d40973db67235df48`, pinned in `k8s/server.yaml`); app 2.41.0 published (`car-2.41.0`).
 - 2026-10-27 — App 2.41.0, server 2.9.0: **recordings reach the server** (owner: "can we make
   it so that we can upload the logs to an endpoint in the server, and you can get the logs from