feat(effects): migrate battle effects to VFX

- add WebP frame-sequence assets for lightning, electric accent, fire, sunbeam, poison, rain, water, and rounded fog effects
- replace procedural lightning rendering with VFX frame playback
- align lightning impact to the click point
- remove the full-screen lightning blur/flash overlay
- add electric accent playback for lightning impact dispersion
- keep lightning scorch marks as the persistent ground trace after the action effect
- consolidate the lightning tool into a single public `Молния` action
- replace procedural fire with the VFX fire implementation
- remove the separate `Огонь 2` tool and keep the VFX fire under `Огонь`
- keep VFX fire brightness fixed at full intensity
- preserve fire as a field effect with brush placement and eraser support
- replace procedural sunbeam with the Pulse Discharge VFX implementation
- remove the separate `Луч света 2` tool and keep the VFX sunbeam under `Луч света`
- align sunbeam impact to the click point instead of the raw frame center
- remove the full-screen sunbeam flash overlay
- add Dust Burst VFX playback for poison cloud
- tint poison smoke green
- keep the skull glyph rendered above the poison smoke
- align poison smoke bottom to the click point
- remove the old procedural poison cloud implementation
- remove the separate `Яд 2` tool and keep the VFX poison under `Яд`
- replace procedural rain strokes with medium-rain VFX frame playback
- recolor rain frames to gray/light-gray so rain no longer renders black
- preserve rain as a field effect with brush placement and eraser support
- replace static water fill with generated animated water VFX frames
- render water VFX through the existing stroke mask so water keeps the painted brush shape
- preserve water as a field effect with brush placement and eraser support
- replace procedural fog texture generation with Smokey Atmosphere VFX frames
- generate rounded fog VFX frames with soft alpha falloff at the edges
- size each fog VFX stamp to the brush diameter
- remove per-stamp fog drift and rotation so fog elements stay fixed in place
- keep fog animation limited to internal frame playback
- preload VFX frame textures for smoother first use
- cache VFX textures per Pixi instance to avoid duplicate decoding
- filter expired action instances before node synchronization to stop old effects from flashing back during rapid casts
- add brush-stroke erasing for field effects using the same model as scene darkness reveal
- keep whole-instance erasing for action effects
- update effect hit tests for the consolidated VFX action effects
- update effect store pruning for renamed and consolidated action effects
- update control-panel buttons for consolidated fire, sunbeam, poison, and VFX-backed field effects
- update editor localization for removed and renamed effect tools
- add tests for field-effect brush erasing
- update eraser hit-test coverage for VFX-backed effects
- update effects store lifetime pruning tests for consolidated poison
- update control-panel tests for consolidated effect buttons
- include the field-effect eraser test in the default test script

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

app/shared/effectEraserHitTest.ts

@@ -63,14 +63,19 @@ export function minDistSqEffectToPoint(inst: EffectInstance, p: { x: number; y:
 }
 
 function eraseHitThresholdSq(inst: EffectInstance, toolRadiusN: number): number {
-  if (inst.type === 'scorch' || inst.type === 'ice' || inst.type === 'shadow' || inst.type === 'poisonCloud') {
+  if (
+    inst.type === 'scorch' ||
+    inst.type === 'ice' ||
+    inst.type === 'shadow' ||
+    inst.type === 'poisonCloud'
+  ) {
     const r = toolRadiusN + inst.radiusN;
     return r * r;
   }
   return toolRadiusN * toolRadiusN;
 }
 
-/** Ближайший эффект в пределах радиуса ластика, иначе `null`. */
+/** Ближайший эффект действия в пределах радиуса ластика, иначе `null`. Эффекты поля стираются кистью отдельно. */
 export function pickEraseTargetId(
   instances: readonly EffectInstance[],
   p: { x: number; y: number },
@@ -78,6 +83,9 @@ export function pickEraseTargetId(
 ): string | null {
   let best: { id: string; dd: number } | null = null;
   for (const inst of instances) {
+    if (inst.type === 'fog' || inst.type === 'fire' || inst.type === 'rain' || inst.type === 'water') {
+      continue;
+    }
     const dd = minDistSqEffectToPoint(inst, p);
     const th = eraseHitThresholdSq(inst, toolRadiusN);
     if (dd <= th && (!best || dd < best.dd)) {