feat: sound

- add SoundManager class to handle bgm and sfx
- add script to generate wav sound assets
- integrate sfx for shop purchases and player transform
- add dynamic bgm switching based on player state
- add sound file paths and volume configurations to settings

src/sounds.py

@@ -0,0 +1,51 @@
+import pygame
+from src.settings import (
+    SFX_TOWER_SHOOT, SFX_MONSTER_HIT, SFX_BUY_SUCCESS,
+    SFX_BUY_FAIL, SFX_MONSTER_HEALED, SFX_MONSTER_TRANSFORM,
+    BGM_NORMAL, BGM_CREEPY, VOLUME_SFX, VOLUME_BGM
+)
+
+class SoundManager:
+    def __init__(self):
+        pygame.mixer.init()
+        self.effects = {}
+        self.current_bgm = None
+
+        self._load_sfx("tower_shoot", SFX_TOWER_SHOOT)
+        self._load_sfx("monster_hit", SFX_MONSTER_HIT)
+        self._load_sfx("buy_success", SFX_BUY_SUCCESS)
+        self._load_sfx("buy_fail", SFX_BUY_FAIL)
+        self._load_sfx("monster_healed", SFX_MONSTER_HEALED)
+        self._load_sfx("monster_transform", SFX_MONSTER_TRANSFORM)
+
+        # set volume via settings param
+        for sound in self.effects.values():
+            if sound:
+                sound.set_volume(VOLUME_SFX)
+
+    def _load_sfx(self, name, path):
+        try:
+            self.effects[name] = pygame.mixer.Sound(path)
+        except pygame.error:
+            print(f"Could not find sound: {path}")
+            self.effects[name] = None
+
+    def play_sfx(self, name):
+        sound = self.effects.get(name)
+        if isinstance(sound, pygame.mixer.Sound):
+            sound.play()
+
+    # set BackGroundMusic dependent if monster is active or tutor is active
+    def play_bgm(self, mode):
+        if self.current_bgm == mode:
+            return
+
+        path = BGM_NORMAL if mode == "normal" else BGM_CREEPY
+
+        try:
+            pygame.mixer.music.load(path)
+            pygame.mixer.music.set_volume(VOLUME_BGM)
+            pygame.mixer.music.play(-1)
+            self.current_bgm = mode
+        except pygame.error:
+            print(f"Could not find sound: {path}")