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/spec/services/ops/notifier_spec.rb

@@ -0,0 +1,43 @@
+require "rails_helper"
+
+RSpec.describe Ops::Notifier do
+  let(:incident) do
+    Ops::Incident.create!(
+      kind: "test",
+      severity: "critical",
+      status: "open",
+      title: "Test alert",
+      message: "Messaggio di prova",
+      metadata: {},
+      fingerprint: "test:#{SecureRandom.hex(4)}",
+      occurrence_count: 1,
+      first_seen_at: Time.current,
+      last_seen_at: Time.current
+    )
+  end
+
+  describe "#notify" do
+    it "invia POST a ntfy quando configurato" do
+      conn = instance_double(Faraday::Connection)
+      response = instance_double(Faraday::Response, success?: true, status: 200, body: "")
+      allow(Faraday).to receive(:new).and_return(conn)
+      allow(conn).to receive(:post).and_return(response)
+      allow(ENV).to receive(:[]).and_call_original
+      allow(ENV).to receive(:[]).with("OPS_NTFY_URL").and_return("https://ntfy.example/ops")
+
+      described_class.new.notify(incident)
+
+      expect(conn).to have_received(:post).with("https://ntfy.example/ops", anything, hash_including("Title"))
+    end
+  end
+
+  describe ".notify_severity?" do
+    it "rispetta OPS_NOTIFY_SEVERITIES" do
+      allow(ENV).to receive(:fetch).and_call_original
+      allow(ENV).to receive(:fetch).with("OPS_NOTIFY_SEVERITIES", "critical").and_return("critical,warning")
+
+      expect(described_class.notify_severity?("critical")).to be(true)
+      expect(described_class.notify_severity?("info")).to be(false)
+    end
+  end
+end