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/app/models/ops/incident.rb

@@ -0,0 +1,43 @@
+module Ops
+  class Incident < ApplicationRecord
+    self.table_name = "ops_incidents"
+
+    KINDS = %w[
+      disk_space recordings_size service_down http_public sidekiq_stale sidekiq_dead
+      log_pattern garage_storage
+    ].freeze
+    SEVERITIES = %w[critical warning info].freeze
+    STATUSES = %w[open acknowledged resolved].freeze
+
+    validates :kind, :severity, :status, :title, :fingerprint, presence: true
+    validates :severity, inclusion: { in: SEVERITIES }
+    validates :status, inclusion: { in: STATUSES }
+    validates :occurrence_count, numericality: { greater_than: 0 }
+
+    scope :open, -> { where(status: %w[open acknowledged]) }
+    scope :unresolved, -> { where.not(status: "resolved") }
+    scope :critical_open, -> { open.where(severity: "critical") }
+    scope :recent, -> { order(last_seen_at: :desc) }
+    scope :since, ->(time) { where("last_seen_at >= ?", time) }
+
+    def open?
+      status.in?(%w[open acknowledged])
+    end
+
+    def muted?
+      muted_until.present? && muted_until.future?
+    end
+
+    def acknowledge!
+      update!(status: "acknowledged", acknowledged_at: Time.current)
+    end
+
+    def resolve!
+      update!(status: "resolved")
+    end
+
+    def mute!(duration: 24.hours)
+      update!(muted_until: duration.from_now)
+    end
+  end
+end