feat: integrate daily challenges, codex recording, and unlock triggers

- Add DailyMode/DailyDate fields to GameSession; use daily seed for floor generation
- Add [D] Daily Challenge button in lobby for solo daily sessions
- Record codex entries for monsters and shop items during gameplay
- Trigger unlock checks (fifth_class, hard_mode, mutations) on game over
- Trigger title checks (novice, explorer, veteran, champion, gold_king) on game over
- Save daily records on game over for daily mode sessions
- Add daily leaderboard tab with Tab key cycling in leaderboard view

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

game/session.go

@@ -84,6 +84,8 @@ type GameSession struct {
 	lastActivity   map[string]time.Time // fingerprint -> last activity time
 	HardMode       bool
 	ActiveMutation *Mutation
+	DailyMode      bool
+	DailyDate      string
 }
 
 type playerActionMsg struct {
@@ -210,7 +212,12 @@ func (s *GameSession) AddPlayer(p *entity.Player) {
 func (s *GameSession) StartFloor() {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	s.state.Floor = dungeon.GenerateFloor(s.state.FloorNum, rand.New(rand.NewSource(time.Now().UnixNano())))
+	if s.DailyMode {
+		seed := DailySeed(s.DailyDate) + int64(s.state.FloorNum)
+		s.state.Floor = dungeon.GenerateFloor(s.state.FloorNum, rand.New(rand.NewSource(seed)))
+	} else {
+		s.state.Floor = dungeon.GenerateFloor(s.state.FloorNum, rand.New(rand.NewSource(time.Now().UnixNano())))
+	}
 	s.state.Phase = PhaseExploring
 	s.state.TurnNum = 0
 

game/turn.go

@@ -373,7 +373,12 @@ func (s *GameSession) advanceFloor() {
 		p.Skills.Points++
 	}
 	s.state.FloorNum++
-	s.state.Floor = dungeon.GenerateFloor(s.state.FloorNum, rand.New(rand.NewSource(time.Now().UnixNano())))
+	if s.DailyMode {
+		seed := DailySeed(s.DailyDate) + int64(s.state.FloorNum)
+		s.state.Floor = dungeon.GenerateFloor(s.state.FloorNum, rand.New(rand.NewSource(seed)))
+	} else {
+		s.state.Floor = dungeon.GenerateFloor(s.state.FloorNum, rand.New(rand.NewSource(time.Now().UnixNano())))
+	}
 	s.state.Phase = PhaseExploring
 	s.state.CombatTurn = 0
 	s.addLog(fmt.Sprintf("Descending to B%d...", s.state.FloorNum))