feat(effects): extinguish fire with water/rain and ambient SFX volume

Water and rain erase fire under a tight brush hit radius; add looping fire/rain ambients and an Effects sound slider that also scales one-shot effect SFX.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/control/poisonCloudSfx.ts

@@ -1,5 +1,7 @@
 /** Звук и длительность эффекта «Облако яда» (`public/oblako-yada.mp3`). */
 
+import { getEffectsSfxGain } from './effectsSfxGain';
+
 const POISON_CLOUD_SFX_VOLUME = 0.92;
 
 /** Запас, если метаданные не прочитались. */
@@ -50,7 +52,7 @@ export async function playPoisonCloudEffectSound(lifeMs: number): Promise<void>
     const target = Math.max(200, lifeMs);
     const rate = Math.max(0.25, Math.min(4, rawMs / target));
     const el = new Audio(poisonCloudEffectSoundUrl());
-    el.volume = POISON_CLOUD_SFX_VOLUME;
+    el.volume = Math.max(0, Math.min(1, POISON_CLOUD_SFX_VOLUME * getEffectsSfxGain()));
     el.playbackRate = rate;
     void el.play().catch(() => undefined);
   } catch {