feat(tournament): implement hunting tournament system end-to-end

Wire format for MsgMhfEnterTournamentQuest (0x00D2) derived from
mhfo-hd.dll binary analysis (FUN_114f4280). Five new tables back
the full lifecycle: schedule, cups, sub-events, player registrations,
and run submissions. All six tournament handlers are now DB-driven:

- EnumerateRanking: returns active tournament schedule with cups and
  sub-events; computes phase state byte from timestamps
- EnumerateOrder: returns per-event leaderboard ranked by submission
  time, with SJIS-encoded character and guild names
- InfoTournament: exposes tournament detail and player registration
  state across all three query types
- EntryTournament: registers player and returns entry handle used by
  the client in the subsequent EnterTournamentQuest packet
- EnterTournamentQuest: parses the previously-unimplemented packet and
  records the run in tournament_results
- AcquireTournament: stubs rewards (item IDs not yet reversed)

Seed data (TournamentDefaults.sql) reproduces tournament #150 cups and
sub-events so a fresh install has a working tournament immediately.

server/channelserver/handlers_simple_test.go

@@ -33,16 +33,18 @@ func TestHandlerMsgMhfSexChanger(t *testing.T) {
 
 func TestHandlerMsgMhfEnterTournamentQuest(t *testing.T) {
 	server := createMockServer()
+	server.tournamentRepo = &mockTournamentRepo{}
 	session := createMockSession(1, server)
 
-	// Should not panic with nil packet (empty handler)
+	pkt := &mhfpacket.MsgMhfEnterTournamentQuest{AckHandle: 1}
+
 	defer func() {
 		if r := recover(); r != nil {
 			t.Errorf("handleMsgMhfEnterTournamentQuest panicked: %v", r)
 		}
 	}()
 
-	handleMsgMhfEnterTournamentQuest(session, nil)
+	handleMsgMhfEnterTournamentQuest(session, pkt)
 }
 
 func TestHandlerMsgMhfGetUdBonusQuestInfo(t *testing.T) {
@@ -295,7 +297,6 @@ func TestEmptyHandlers_NoDb(t *testing.T) {
 		{"handleMsgSysSetStatus", handleMsgSysSetStatus},
 		{"handleMsgSysEcho", handleMsgSysEcho},
 		{"handleMsgMhfUseUdShopCoin", handleMsgMhfUseUdShopCoin},
-		{"handleMsgMhfEnterTournamentQuest", handleMsgMhfEnterTournamentQuest},
 	}
 
 	for _, tt := range tests {