Introduce architettura multi-sport con catalogo, engine scoring e overlay.

Catalogo sport in YAML, board implicito, engine per volley/basket/timed/racket/timer/generic, regia e app Android allineate.

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

backend/app/helpers/public/regia_helper.rb

@@ -0,0 +1,32 @@
+module Public
+  module RegiaHelper
+    def regia_board_partial(match)
+      board = match.effective_board_type
+      partial = "public/regia/#{board}"
+      lookup_context.exists?(partial, [], true) ? partial : "public/regia/volley"
+    end
+
+    def regia_header_subtitle(match, score)
+      board = match.effective_board_type
+      case board
+      when "basket", "timed"
+        live_score_period_label(match, score)
+      when "timer"
+        "Cronometro"
+      when "generic"
+        "Punteggio"
+      else
+        "Set #{score.current_set}"
+      end
+    end
+
+    def format_clock_secs(secs, count_up: false)
+      total = secs.to_i
+      return count_up ? "0:00" : "—" if total <= 0 && !count_up
+
+      m = total / 60
+      s = total % 60
+      format("%d:%02d", m, s)
+    end
+  end
+end