ci(smoke): cover teardown, state transitions and fake hardware

The smoke test only exercised steady-state rendering and killed waybar with
SIGTERM, so whole crash classes were invisible: exit-time use-after-free
(#5182), module state transitions (#5183) and hardware-backed modules (#5179).
Add tiers that hit those paths under ASan (+ _GLIBCXX_ASSERTIONS):

- lib.sh: assert_clean_exit (SIGINT teardown -> checks segfault/abort + ASan
  report emitted during destruction), output hotplug helpers, signal/reload,
  WAYBAR_WRAP hook, opt-in leak detection.
- lifecycle.sh (gating): clean exit, runtime output hotplug (Bar/module
  destroy), toggle/reload churn, fast-interval teardown race (#5182 class).
- fuzz.sh (gating): pathological custom-backend output (empty, nonzero exit,
  invalid JSON, huge, non-UTF8, empty format).
- coverage.sh (gating): every Factory module must be classified for smoke
  coverage; a new unlisted module fails the job (#5179 slipped through).
- modules.sh: also render the whole matrix inside a group; SIGINT teardown per
  module instead of SIGTERM.
- state.sh (best-effort): real mpd driven through an empty queue (#5183) +
  stop/clear; pulseaudio + slider on a null sink.
- hardware.sh (best-effort): backlight, backlight/slider (#5179) and battery
  via umockdev.
- leakcheck.sh (report-only): clean-exit run under LSan.

test/smoke/modules.sh

@@ -47,13 +47,35 @@ EOF
         smoke::assert_not_blank "$SHOTDIR/$safe.png" || ok=0
     fi
     [ "$ok" = 1 ] || fails+=("$mod")
-    kill "$WAYBAR_PID" 2>/dev/null || true
-    sleep 1
+    # SIGINT teardown (not SIGTERM) so each module's destructor path is ASan-checked.
+    smoke::assert_clean_exit || fails+=("$mod (exit)")
     echo "::endgroup::"
 done
 
+# --- all modules inside a group -----------------------------------------
+# Group children have a different construct/destroy path than top-level modules
+# (#5179 crashed inside a group), so render the whole matrix wrapped in one.
+echo "::group::modules inside a group"
+mods_json="$(printf '%s\n' "${!MODULES[@]}" | jq -R . | jq -s .)"
+opts_json='{}'
+for mod in "${!MODULES[@]}"; do
+    opts_json="$(jq --arg k "$mod" --argjson v "${MODULES[$mod]}" '. + {($k):$v}' <<<"$opts_json")"
+done
+gcfg="$(mktemp --suffix=.json)"
+jq -n --argjson mods "$mods_json" --argjson opts "$opts_json" '
+  {layer:"top",position:"top",height:30,"modules-center":["group/g"],"group/g":{modules:$mods}} + $opts' \
+  > "$gcfg"
+smoke::launch_waybar "$gcfg" "$DIR/style.css" 5
+ok=1
+smoke::assert_alive || ok=0
+smoke::assert_clean || ok=0
+[ "$ok" = 1 ] && { smoke::screenshot "$SHOTDIR/_group.png"; smoke::assert_not_blank "$SHOTDIR/_group.png" || ok=0; }
+smoke::assert_clean_exit || ok=0
+[ "$ok" = 1 ] || fails+=("group")
+echo "::endgroup::"
+
 if [ "${#fails[@]}" -gt 0 ]; then
     echo "::error::modules failed to render cleanly: ${fails[*]}"
     exit 1
 fi
-echo "✓ all ${#MODULES[@]} modules rendered cleanly"
+echo "✓ all ${#MODULES[@]} modules rendered cleanly (standalone + grouped)"