Add recorder: raw CAN and GNSS sessions with failsafes and a storage bound

Reads SocketCAN and gpsd directly. Sessions start on the first frame or on
'ctl start', end after 15 s of bus idle or on 'ctl stop'; blips under 3 s are
discarded. candump -L chunks fdatasync'd every second and zstd'd once closed;
oldest sessions deleted to stay under 50 GB / above 20 GB free. Kernel and
queue drops, link changes and clock steps are recorded as events.

Bench-tested on vcan with the first car capture (byte-identical) and installed
on the car Orin as yukart-recorder.service.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz

scripts/deploy-recorder.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Build the recorder for aarch64, check it against the car's glibc, and install it
+# on an Orin as the yukart-recorder service.
+#
+#   usage: scripts/deploy-recorder.sh [host]        (default: mikkeli-orin-nano)
+#
+# Cross-compiles from the workstation (the documented fallback): the development
+# Orin is the preferred native build host. Either way check-glibc.sh gates it.
+set -euo pipefail
+
+HOST="${1:-mikkeli-orin-nano}"
+cd "$(dirname "$0")/.."
+TARGET=aarch64-unknown-linux-gnu
+BIN="target/$TARGET/release/recorder"
+
+cargo build --release --target "$TARGET"
+scripts/check-glibc.sh "$BIN"
+
+# Binary lives under ~/infra per the host repo's guidelines; /usr/local/bin gets a symlink.
+ssh "$HOST" 'mkdir -p ~/infra/svc-core'
+scp -q "$BIN" "$HOST:infra/svc-core/recorder.new"
+scp -q deploy/yukart-recorder.service "$HOST:infra/svc-core/yukart-recorder.service"
+ssh "$HOST" 'set -e
+  mv ~/infra/svc-core/recorder.new ~/infra/svc-core/recorder
+  sudo ln -sfn "$HOME/infra/svc-core/recorder" /usr/local/bin/yukart-recorder
+  sudo install -m 0644 ~/infra/svc-core/yukart-recorder.service /etc/systemd/system/yukart-recorder.service
+  sudo systemctl daemon-reload
+  sudo systemctl enable yukart-recorder.service >/dev/null
+  sudo systemctl restart yukart-recorder.service
+  sleep 1
+  systemctl --no-pager --lines=5 status yukart-recorder.service'