Aggiunge monitoraggio ops: health check, log scanner, dashboard e notifiche.

Introduce incidenti con dedup, job Sidekiq ogni 3 min, scan log cron, /up/deep,
dashboard /admin/ops e push ntfy; include Sentry opzionale e fix test suite.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/config/initializers/sentry.rb

@@ -0,0 +1,33 @@
+if ENV["SENTRY_DSN"].present? && !Rails.env.test?
+  begin
+    require "sentry-ruby"
+    require "sentry-rails"
+
+    Sentry.init do |config|
+      config.dsn = ENV["SENTRY_DSN"]
+      config.breadcrumbs_logger = %i[active_support_logger http_logger]
+      config.traces_sample_rate = ENV.fetch("SENTRY_TRACES_SAMPLE_RATE", "0.1").to_f
+      config.environment = Rails.env
+
+      config.before_send = lambda do |event, _hint|
+        Ops::IncidentRecorder.record(
+          kind: "log_pattern",
+          severity: "warning",
+          title: "Sentry: #{event.message}",
+          message: event.message,
+          metadata: {
+            "sentry_event_id" => event.event_id,
+            "level" => event.level
+          },
+          fingerprint: "sentry:#{event.fingerprint&.first || event.event_id}"
+        )
+        event
+      rescue StandardError => e
+        Rails.logger.warn("[Sentry] ops incident hook: #{e.message}")
+        event
+      end
+    end
+  rescue LoadError
+    Rails.logger.warn("[Sentry] gem non installata — imposta SENTRY_DSN dopo bundle add sentry-ruby sentry-rails")
+  end
+end