Club come entità principale, branding e fix infrastruttura streaming.

Introduce clubs con abbonamento, branding Active Storage e flusso registrazione società; corregge healthcheck MediaMTX (immagine distroless) e allinea dominio produzione matchlivetv.it.

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

backend/app/models/user.rb

@@ -5,8 +5,21 @@ class User < ApplicationRecord
 
   has_many :user_teams, dependent: :destroy
   has_many :teams, through: :user_teams
+  has_many :club_memberships, dependent: :destroy
+  has_many :clubs, through: :club_memberships
+  has_many :owned_clubs, -> { where(club_memberships: { role: "owner" }) }, through: :club_memberships, source: :club
   has_many :stream_sessions, dependent: :nullify
 
+  def manageable_teams
+    staff_ids = teams.select(:id)
+    owner_ids = Team.where(club_id: owned_clubs.select(:id)).select(:id)
+    Team.where(id: staff_ids).or(Team.where(id: owner_ids))
+  end
+
+  def primary_club
+    owned_clubs.order(:created_at).first
+  end
+
   validates :email, presence: true, uniqueness: true, format: { with: URI::MailTo::EMAIL_REGEXP }
   validates :name, presence: true
   validates :role, inclusion: { in: ROLES }