feat(restore): mail-archiver restore smoke test

Borg-Extract der Data-Protection-Keys + pg_restore des 645M
mailarchiver-Dumps in isoliertes Test-Postgres + Container-Boot +
HTTP-Smoke. Wegwerf-DB-Connection und Auth-Password, kein produktiver
Stack-ENV, kein Authelia-ForwardAuth im Smoke.

Machbarkeit vorab verifiziert: Dump vorhanden, App-Image gepinnt,
Data-Protection-Keys im Borg, .NET-App hat kein shfs-chmod-Problem.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ops/restore-tests/run-restore-checks.sh

@@ -58,6 +58,12 @@ case "$MODE" in
     fi
     exec "$SCRIPT_DIR/komodo-mongo-restore-test.sh"
     ;;
+  mailarchiver)
+    if [ "$WHATIF" = "--what-if" ]; then
+      exec "$SCRIPT_DIR/mailarchiver-restore-test.sh" --what-if
+    fi
+    exec "$SCRIPT_DIR/mailarchiver-restore-test.sh"
+    ;;
   mealie)
     if [ "$WHATIF" = "--what-if" ]; then
       exec "$SCRIPT_DIR/mealie-restore-test.sh" --what-if