feat: harden dashcam transfer tegen flakke SD-lezer + stale-mount cleanup

- dashcam-transfer.py: log echte OSError (shutil.copy2 i.p.v. cp), pre-flight
  leesbaarheidscheck voor ruimte-wissen, retry (3x) + early-abort (5x), guards
  op bestandssysteem-calls, WhatsApp GESTOPT bij defecte kaart
- dashcam-transfer-mount.sh: skip als service al draait, read-only fsck.exfat
  health check, %k device-naam doorgeven
- dashcam-transfer-cleanup.sh: nieuw - ruimt stale mount op bij udev REMOVE
- udev/99-dashcam-trigger.rules: ADD + REMOVE regels met %k
- tests: 20 python + 7 mount + 12 cleanup checks
- README: architectuur, robuustheid, deploy-instructies

tests/test_cleanup_script.sh

@@ -0,0 +1,118 @@
+#!/bin/bash
+# Functional test for dashcam-transfer-cleanup.sh using fake tools on PATH.
+set -u
+
+SCRIPT="$(cd "$(dirname "$0")/.." && pwd)/dashcam-transfer-cleanup.sh"
+WORK=$(mktemp -d)
+trap 'rm -rf "$WORK"' EXIT
+
+FAKEBIN="$WORK/bin"
+mkdir -p "$FAKEBIN"
+
+LOGGER_FILE="$WORK/logger.log"
+UMOUNT_MARKER="$WORK/umounted"
+LAZY_MARKER="$WORK/lazy"
+STOP_MARKER="$WORK/stopped"
+
+export LOGGER_FILE UMOUNT_MARKER LAZY_MARKER STOP_MARKER FAKE_SRC FAKE_UMOUNT_FAIL
+
+cat > "$FAKEBIN/logger" <<'EOF'
+#!/bin/bash
+echo "logger: $*" >> "$LOGGER_FILE"
+EOF
+
+cat > "$FAKEBIN/findmnt" <<'EOF'
+#!/bin/bash
+if [ -z "$FAKE_SRC" ]; then
+    exit 1
+fi
+echo "$FAKE_SRC"
+EOF
+
+cat > "$FAKEBIN/systemctl" <<'EOF'
+#!/bin/bash
+if [ "$1" = "stop" ]; then
+    touch "$STOP_MARKER"
+fi
+EOF
+
+cat > "$FAKEBIN/umount" <<'EOF'
+#!/bin/bash
+if [ "${1:-}" = "-l" ]; then
+    touch "$LAZY_MARKER"
+    exit 0
+fi
+if [ "$FAKE_UMOUNT_FAIL" = "1" ]; then
+    exit 1
+fi
+touch "$UMOUNT_MARKER"
+EOF
+
+chmod +x "$FAKEBIN"/*
+
+pass=0
+fail=0
+check() { # $1=desc, $2=condition
+    if eval "$2"; then
+        echo "PASS: $1"
+        pass=$((pass + 1))
+    else
+        echo "FAIL: $1"
+        fail=$((fail + 1))
+    fi
+}
+
+reset() {
+    rm -f "$LOGGER_FILE" "$UMOUNT_MARKER" "$LAZY_MARKER" "$STOP_MARKER"
+    unset FAKE_UMOUNT_FAIL
+}
+
+# Test 1: niet gemount → niets te doen
+reset
+FAKE_SRC=""
+PATH="$FAKEBIN:$PATH" "$SCRIPT"
+check "niet gemount → geen umount" 'test ! -e "$UMOUNT_MARKER"'
+check "niet gemount → geen service stop" 'test ! -e "$STOP_MARKER"'
+
+# Test 2: device nog aanwezig → mount blijft
+reset
+FAKE_SRC="$WORK/fake-device"
+touch "$FAKE_SRC"
+PATH="$FAKEBIN:$PATH" "$SCRIPT"
+check "device aanwezig → geen umount" 'test ! -e "$UMOUNT_MARKER"'
+check "device aanwezig → geen service stop" 'test ! -e "$STOP_MARKER"'
+
+# Test 3: device verdwenen → stop + umount
+reset
+FAKE_SRC="$WORK/gone-device"
+PATH="$FAKEBIN:$PATH" "$SCRIPT"
+check "device weg → service gestopt" 'test -e "$STOP_MARKER"'
+check "device weg → umount uitgevoerd" 'test -e "$UMOUNT_MARKER"'
+check "device weg → geen lazy nodig" 'test ! -e "$LAZY_MARKER"'
+
+# Test 4: umount mislukt → lazy umount
+reset
+FAKE_SRC="$WORK/gone-device"
+export FAKE_UMOUNT_FAIL=1
+PATH="$FAKEBIN:$PATH" "$SCRIPT"
+check "umount faalt → lazy umount" 'test -e "$LAZY_MARKER"'
+
+# Test 5: node bestaat nog maar source = verwijderd device → stale
+reset
+mkdir -p "$WORK/dev"
+touch "$WORK/dev/sde1"
+FAKE_SRC="$WORK/dev/sde1"
+PATH="$FAKEBIN:$PATH" "$SCRIPT" sde1
+check "source matcht verwijderd device → umount" 'test -e "$UMOUNT_MARKER"'
+check "source matcht verwijderd device → service gestopt" 'test -e "$STOP_MARKER"'
+
+# Test 6: ander device verwijdert, sdcard-healthy → niets doen
+reset
+touch "$WORK/dev/sdb2"
+FAKE_SRC="$WORK/dev/sde1"
+PATH="$FAKEBIN:$PATH" "$SCRIPT" sdb2
+check "ander device → geen umount" 'test ! -e "$UMOUNT_MARKER"'
+check "ander device → geen service stop" 'test ! -e "$STOP_MARKER"'
+
+echo "=== $pass pass, $fail fail ==="
+[ "$fail" -eq 0 ]