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.test.ts

@@ -6,7 +6,7 @@ import type { EffectInstance } from './types/effects';
 
 const base = { seed: 1, createdAtMs: 0 };
 
-void test('pickEraseTargetId: fire/rain по штриху как туман', () => {
+void test('pickEraseTargetId: fire/rain/water — кистью, не целиком', () => {
   const fire: EffectInstance = {
     ...base,
     id: 'f1',
@@ -17,10 +17,10 @@ void test('pickEraseTargetId: fire/rain по штриху как туман', ()
     lifetimeMs: null,
   };
   const id = pickEraseTargetId([fire], { x: 0.51, y: 0.5 }, 0.05);
-  assert.equal(id, 'f1');
+  assert.equal(id, null);
 });
 
-void test('pickEraseTargetId: вода по штриху как туман', () => {
+void test('pickEraseTargetId: вода — кистью, не целиком', () => {
   const water: EffectInstance = {
     ...base,
     id: 'w1',
@@ -31,7 +31,7 @@ void test('pickEraseTargetId: вода по штриху как туман', ()
     lifetimeMs: null,
   };
   const id = pickEraseTargetId([water], { x: 0.41, y: 0.55 }, 0.05);
-  assert.equal(id, 'w1');
+  assert.equal(id, null);
 });
 
 void test('pickEraseTargetId: тьма как заморозка — точка удара', () => {
@@ -108,3 +108,17 @@ void test('pickEraseTargetId: scorch с учётом inst.radiusN', () => {
   const id = pickEraseTargetId([sc], { x: 0.59, y: 0.5 }, 0.02);
   assert.equal(id, 's1');
 });
+
+void test('pickEraseTargetId: яд с учётом inst.radiusN', () => {
+  const pc: EffectInstance = {
+    ...base,
+    id: 'pc',
+    type: 'poisonCloud',
+    at: { x: 0.5, y: 0.5 },
+    radiusN: 0.08,
+    intensity: 1,
+    lifetimeMs: 1000,
+  };
+  const id = pickEraseTargetId([pc], { x: 0.59, y: 0.5 }, 0.02);
+  assert.equal(id, 'pc');
+});