test: one command for every recovery property the room depends on

Run against the lab as the package built it, not a session edited by
hand. The panel came back from eight SIGKILLs a second apart in about
2.2s each time, the compositor in 0.1s, the audio policy from three, and
neither Parent Call nor the browser dying disturbed the panel.

Co-Authored-By: Claude Opus 5 <[email protected]>

tools/lab/recovery-check

@@ -0,0 +1,81 @@
+#!/bin/bash
+# Every recovery property the classroom depends on, measured against the
+# lab as the package built it. Run after tools/lab/from-package.
+set -uo pipefail
+
+NAME="${LAB_NAME:-classroom-v2-lab}"
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+
+inlab() { docker exec "$NAME" "$@"; }
+insession() {
+    docker exec -u classroom -e XDG_RUNTIME_DIR=/run/user/1000 \
+        -e DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus \
+        -e HOME=/home/classroom "$NAME" "$@"
+}
+
+kill_and_wait() {
+    local proc="$1" rounds="${2:-1}" gap="${3:-1}"
+    for round in $(seq 1 "$rounds"); do
+        local old new started
+        old=$(inlab pgrep -x "$proc" | head -1)
+        [ -n "$old" ] || { echo "  $proc was not running"; return 1; }
+        started=$(date +%s%N)
+        inlab kill -9 "$old" 2>/dev/null
+        new=""
+        while [ $(( ($(date +%s%N) - started) / 1000000000 )) -lt 60 ]; do
+            new=$(inlab pgrep -x "$proc" | head -1)
+            [ -n "$new" ] && [ "$new" != "$old" ] && break
+            sleep 0.25
+        done
+        if [ -n "$new" ] && [ "$new" != "$old" ]; then
+            printf "  %-16s round %s: back in %ss\n" "$proc" "$round" \
+                "$(awk "BEGIN{printf \"%.1f\", ($(date +%s%N)-$started)/1000000000}")"
+        else
+            printf "  %-16s round %s: DID NOT COME BACK\n" "$proc" "$round"
+            return 1
+        fi
+        sleep "$gap"
+    done
+}
+
+echo "the panel, killed eight times a second apart"
+kill_and_wait plasmashell 8 1
+
+echo
+echo "the compositor, killed twice"
+kill_and_wait kwin_wayland 2 4
+
+echo
+echo "the audio policy, killed three times"
+for round in 1 2 3; do
+    inlab pkill -9 -f "bin/classroom-audio" 2>/dev/null
+    sleep 6
+    printf "  audio round %s: %s\n" "$round" \
+        "$(insession systemctl --user is-active ekklesia-classroom-audio.service)"
+done
+
+echo
+echo "Parent Call, killed while the panel is watched"
+insession sh -c 'setsid /usr/local/bin/classroom-parent-call >/dev/null 2>&1 &'
+sleep 5
+before=$(inlab pgrep -c -x plasmashell)
+inlab pkill -9 -f "bin/classroom-parent-call" 2>/dev/null
+sleep 3
+printf "  panel before %s, after %s\n" "$before" "$(inlab pgrep -c -x plasmashell)"
+
+echo
+echo "the browser, killed while the panel is watched"
+insession sh -c 'setsid /usr/local/bin/classroom-browser >/dev/null 2>&1 &'
+sleep 18
+before=$(inlab pgrep -c -x plasmashell)
+inlab pkill -9 chrome 2>/dev/null
+sleep 4
+printf "  panel before %s, after %s\n" "$before" "$(inlab pgrep -c -x plasmashell)"
+
+echo
+echo "what is still standing"
+printf "  plasmashell=%s kwin=%s applets=%s audio=%s\n" \
+    "$(inlab pgrep -c -x plasmashell)" \
+    "$(inlab pgrep -c -x kwin_wayland)" \
+    "$(inlab sh -c 'grep -c "^plugin=" /home/classroom/.config/plasma-org.kde.plasma.desktop-appletsrc')" \
+    "$(insession systemctl --user is-active ekklesia-classroom-audio.service)"