Fix wallpaper scan cap exit status

tests/quickshell/wallpaper-service-contract

@@ -4,6 +4,7 @@ set -euo pipefail
 
 repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
 service="$repo_dir/config/dot/quickshell/services/Wallpaper.qml"
+scanner="$repo_dir/config/dot/quickshell/scripts/panama-wallpaper-scan"
 fixture="$(mktemp -d /tmp/panama-wallpaper-service.XXXXXX)"
 config_home="$fixture/config"
 state_home="$fixture/state"
@@ -17,6 +18,8 @@ shell_log="$fixture/quickshell.log"
 harness_pid=""
 quoted_home="$fixture/home's"
 quoted_wallpaper="$quoted_home/Pictures/Wallpapers/quoted.jpg"
+bulk_wallpapers="$fixture/bulk-wallpapers"
+bulk_segment="wallpaper-root-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 
 fail() {
     printf 'wallpaper service contract: %s\n' "$1" >&2
@@ -48,10 +51,26 @@ cleanup() {
 }
 trap cleanup EXIT
 
+for _ in $(seq 1 15); do
+    bulk_wallpapers="$bulk_wallpapers/$bulk_segment"
+done
 mkdir -p "$config_home/panama" "$state_home" "$test_bin" \
-    "$quoted_home/Pictures/Wallpapers"
+    "$quoted_home/Pictures/Wallpapers" "$bulk_wallpapers"
 cp -a "$repo_dir/config/dot/quickshell" "$config_path"
 printf 'quoted wallpaper\n' >"$quoted_wallpaper"
+for index in $(seq 1 401); do
+    wallpaper="$bulk_wallpapers/wallpaper-$index.jpg"
+    printf 'bulk wallpaper %s\n' "$index" >"$wallpaper"
+    touch -d "@$((1700000000 + index))" "$wallpaper"
+done
+if ! bulk_scan="$("$scanner" "$bulk_wallpapers")"; then
+    fail 'a normal scan with more than 60 images exited non-zero'
+fi
+expected_bulk_scan="$(for index in $(seq 401 -1 342); do
+    printf '%s\n' "$bulk_wallpapers/wallpaper-$index.jpg"
+done)"
+[[ "$bulk_scan" == "$expected_bulk_scan" ]] \
+    || fail "over-cap scan did not emit exactly the newest 60 images: $bulk_scan"
 cat >"$config_home/panama/settings.json" <<'JSON'
 {
   "displays": {