feat(game): void unreplayable games as a draw instead of erroring

A committed move that becomes illegal under a tightened rule (the single-word
connectivity fix) makes engine replay fail, which left such games unopenable —
an empty screen and an 'illegal play' error. Now the first open closes the game
gracefully as a draw (engine.EndAborted -> end_reason 'aborted', no winner),
preserves the journal, and surfaces an impersonal organizer note at the end of
the move history and in the GCG export.

- engine: EndAborted + Abort() (draw, no rack adjustment; winner -1).
- service: replay aborts on ErrIllegalPlay; liveGame persists the void once
  (lazy, on open); GameState re-reads for the settled view.
- store: VoidGame finishes the game and stamps a draw without a journal row.
- migration 00002: allow end_reason 'aborted'.
- ui: organizer note under the history grid; i18n en/ru.
- docs: ARCHITECTURE 6/9.1, FUNCTIONAL(+ru), PRERELEASE MW3.

backend/internal/game/gcg.go

@@ -36,6 +36,11 @@ func writeGCG(g Game, names []string, moves []HistoryMove) string {
 			fmt.Fprintf(&b, "#note %s timed out (rack %s)\n", nick(mv.Seat), rack)
 		}
 	}
+	// An aborted game ends in a draw because it could no longer be reconstructed; record it
+	// as an impersonal organizer note (free-text #note; GCG readers ignore pragmas).
+	if g.EndReason == "aborted" {
+		fmt.Fprintln(&b, "#note [organizer] game could not be continued and was ended in a draw")
+	}
 	return b.String()
 }