Add AI Romance Companion system 💕

User insight: "This works as a romance companion!"

Absolutely brilliant! Memory scoring + AI reactions = Perfect romance game

## New Features

### 💕 AI Companion System
Create your personal AI companion with 5 personality types:
- ⚡ Energetic (adventurous) - Matches with Innovators
- 📚 Intellectual (thoughtful) - Matches with Philosophers
- 🎯 Practical (reliable) - Matches with Pragmatists
- 🌙 Dreamy (romantic) - Matches with Visionaries
- ⚖️ Balanced - Matches with Analysts

### 🎮 How It Works
1. Create memory with AI → Get priority score
2. Show memory to companion → She reacts!
3. High score memory → Better reaction
4. Affection ↑ XP ↑ Trust ↑ Level ↑

### 💕 Relationship Mechanics
- **Affection Score**: 0.0-1.0 (displayed as hearts ❤️🤍)
- **Compatibility System**: Your type × Her personality = Bonus
- **Level System**: Gain XP from interactions
- **Trust System**: Build up to 100
- **Special Events**: Max affection, Level 10, etc.

### 🎊 Special Events
- Max Affection Event: Confession!
- Level 10: Deep relationship milestone
- Max Trust: Complete trust achieved

## Implementation

New file: `src/companion.rs`
- Companion struct with personality
- CompanionPersonality enum (5 types)
- React to memory based on score & type
- Compatibility calculation
- Special event triggers
- Daily message generation

MCP Tools:
- create_companion: Create your companion
- companion_react: Show memory & get reaction
- companion_profile: View stats

Game Display:
```
╔══════════════════════════════════════╗
║       💕 エミリー の反応            ║
╚══════════════════════════════════════╝

⚡ エミリー:
「すごい！あなたのアイデア、本当に好き！」

💕 好感度: ❤️❤️🤍🤍🤍🤍🤍🤍🤍🤍 15%
💎 XP獲得: +850 XP
🎊 レベルアップ！
```

## Why This Is Perfect

Memory Score = Romance Game Mechanics:
- LEGENDARY memory → "Amazing! I love you!"
- EPIC memory → "That's so cool about you!"
- High compatibility → Faster relationship growth
- Your actual thoughts → Personal reactions

It's like a dating sim where the relationship grows based on your REAL thoughts and ideas, not scripted choices!

Next: Persistence, more events, character customization

src/game_formatter.rs

@@ -64,6 +64,17 @@ pub enum DiagnosisType {
 }
 
 impl DiagnosisType {
+    /// スコアから診断タイプを推定（公開用）
+    pub fn from_memory(memory: &crate::memory::Memory) -> Self {
+        // スコア内訳を推定
+        let emotional = (memory.priority_score * 0.25).min(0.25);
+        let relevance = (memory.priority_score * 0.25).min(0.25);
+        let novelty = (memory.priority_score * 0.25).min(0.25);
+        let utility = memory.priority_score - emotional - relevance - novelty;
+
+        Self::from_score_breakdown(emotional, relevance, novelty, utility)
+    }
+
     pub fn from_score_breakdown(
         emotional: f32,
         relevance: f32,