Implement pet nicknames system - database, IRC command, validation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/database.py

@@ -1316,4 +1316,46 @@ class Database:
                 "total_encounters": total_encounters,
                 "total_species": total_species,
                 "completion_percentage": round(completion_percentage, 1)
+            }
+    
+    async def set_pet_nickname(self, player_id: int, pet_identifier: str, nickname: str) -> Dict:
+        """Set a nickname for a pet. Returns result dict."""
+        # Validate nickname
+        if not nickname.strip():
+            return {"success": False, "error": "Nickname cannot be empty"}
+        
+        nickname = nickname.strip()
+        if len(nickname) > 20:
+            return {"success": False, "error": "Nickname must be 20 characters or less"}
+        
+        # Basic content validation
+        if any(char in nickname for char in ['<', '>', '&', '"', "'"]):
+            return {"success": False, "error": "Nickname contains invalid characters"}
+        
+        async with aiosqlite.connect(self.db_path) as db:
+            db.row_factory = aiosqlite.Row
+            
+            # Find pet by current nickname or species name
+            cursor = await db.execute("""
+                SELECT p.*, ps.name as species_name
+                FROM pets p
+                JOIN pet_species ps ON p.species_id = ps.id
+                WHERE p.player_id = ? 
+                AND (p.nickname = ? OR ps.name = ?)
+                LIMIT 1
+            """, (player_id, pet_identifier, pet_identifier))
+            
+            pet = await cursor.fetchone()
+            if not pet:
+                return {"success": False, "error": f"Pet '{pet_identifier}' not found"}
+            
+            # Update nickname
+            await db.execute("UPDATE pets SET nickname = ? WHERE id = ?", (nickname, pet["id"]))
+            await db.commit()
+            
+            return {
+                "success": True, 
+                "pet": dict(pet),
+                "old_name": pet["nickname"] or pet["species_name"],
+                "new_nickname": nickname
             }