monitoring: host-agent HTML, surface, aptdeploy, sticky bar

Complete taler-monitoring host-agent (hacktivism/surface/aptdeploy timers),
site-gen console HTML with sticky status bar and collapsible scope, apt-src
deploy tests, remote surface inventory, and Caddy monitoring handle snippets.

scripts/taler-monitoring/host-agent/touch-software-stamp.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+# Call after upgrading hacktivism packages / redeploying landings / image rebuilds.
+# systemd path unit watches this stamp → re-runs monitoring.
+set -euo pipefail
+STATE="${XDG_STATE_HOME:-$HOME/.local/state}/taler-hacktivism-monitoring"
+mkdir -p "$STATE"
+STAMP="$STATE/software.stamp"
+date -Iseconds >"$STAMP"
+# also record container image ids for debugging
+if command -v podman >/dev/null 2>&1; then
+  {
+    echo "# images $(date -Iseconds)"
+    podman images --format '{{.Repository}}:{{.Tag}} {{.ID}} {{.Digest}}' 2>/dev/null | grep -i hacktivism || true
+    podman ps --format '{{.Names}} {{.ImageID}} {{.Status}}' 2>/dev/null | grep -i hacktivism || true
+  } >"$STATE/software-images.txt" || true
+fi
+echo "touched $STAMP"