1.2.1.1-beta: notification + LXC + post-install fixes

- flask_notification_routes: PVE webhook X-Webhook-Secret written in
  standard base64 so PVE can decode it (GH #198)
- notification_channels: Gmail SMTP App Password handling — normalize
  tls_mode (None/empty → starttls), reject creds without host (false-
  positive sendmail delivery), surface "AUTH not advertised" hint
- notification_events: is_vzdump_active_on_host() reads /var/log/pve/
  tasks/active directly so backup_start fallback and vm_shutdown
  suppression survive a Monitor restart mid-backup
- notification_templates: extract --storage flag from vzdump log →
  "PBS-Cloud: vm/104/…" instead of generic "PBS:" prefix when multiple
  PBS endpoints exist
- health_monitor: pve_storage_capacity + zfs_pool_capacity respect
  per-item dismiss (don't keep category WARNING/CRITICAL after user
  dismisses); updates_check cache invalidated when /var/log/apt/
  history.log mtime advances
- lxc_mount_points: PVE volume size from subvol quota (df via
  /proc/<host_pid>/root/<target> + lxc.conf size=NNNG fallback);
  host_source_state detects "host detached" zombie binds; per-mount
  subprocess work parallelised via ThreadPoolExecutor so a CT with
  many bind mounts doesn't trip the Caddy 3s reverse-proxy timeout
- virtual-machines: "host detached" badge on bind mounts whose host
  source path disappeared
- auto/customizable_post_install: log2ram FUNC_VERSION 1.1 → 1.2; new
  log2ram-check.sh vacuums journal + truncates non-rotating logs
  (pveproxy/access.log, pveam.log) instead of only calling
  `log2ram write` (which leaves the tmpfs full); auto flow gains the
  missing SystemMaxUse in /etc/systemd/journald.conf

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

AppImage/ProxMenux-Monitor.AppImage.sha256

@@ -1 +1 @@
-6249ae8d51e0d7dbd3035ba49f4244ff035c2c6d97d5c55f69ab0dac6a4ea021  ProxMenux-1.2.1.1-beta.AppImage
+70a510025df81652319d16e0d36e77bea95a965163608232e9aca60ada9c9fbf  ProxMenux-1.2.1.1-beta.AppImage