GitHub PR #386 by @leiming2333 (this commit is substantially the PR: its blizzard particles and flash). The official
blizzard blows bottom-up (the owner's confirmation of 2026-10-08; community report 「谢拉格的效果特性不明显，暴风雪应该
从下向上刮」): snowflakes rise off the bottom edge on a crosswind (48, low 22; were 26 drifting down), 10 gust streaks
(low 4) race up through the field, and the cold flash goes from 0.35 / 0.8 s to 0.45 / 1 s. Counts, speeds and lives
are marked [ASSUMED] (a visual choice).
Added on top of the PR: the same 'chill' fx is also the coldWind of 灵知 S3 (失温症, at its start) and of 麦哲伦 S1's
pulse (every 3 s — 248 in one golden battle); the PR turned every one of them into the full-screen blizzard. Only the
bond's field-wide wind (the device emits no anchor unit) gets it now; an operator's own coldWind (`id` = the unit)
keeps the light flurry and the softer flash it had.
Tests: test/render/fxchill.test.js (2; the gust case fails on the parent). Display only: golden unchanged.
Cause: 引星棘刺 S2's drifting alchemy unit is re-sent every second (position and radius change) and the client drew each
event as a new additive zone lasting the rest of the unit's life — up to twelve layers on one spot; overlapping units
(锡人's charges, several alchemists) added up the same way (render/fx/zones.js: disc alpha 0.28, edge 0.75, ADD blend).
Now: the sim fx carries `key` (kits/ops/chess_char_5_15-thorn2.js) and zones.js updates the zone under that key in place;
zoneAlpha draws a persistent area (> 3 real s) at 0.16 / 0.5 and ÷ √n among the n persistent areas overlapping it (centres
closer than ¾ of their radii summed); short bursts and telegraphs unchanged.
Golden: unchanged (fx events are counted by kind; the snapshots do not carry fx).
Tests: test/render/feedback5-zone-stack.test.js (3, fail on the parent).
public/js/render/fx.js becomes a re-export barrel. Speeds, camera heights, fonts, the kind table and the shared tunables move verbatim into public/js/render/fx/*.js. FxSystem keeps its constructor, clear, update, counts and destroy; the other methods move verbatim into container classes installed on FxSystem.prototype in source order. simSpeeds and fontsReady each stay one instance. The dynamic import of /sim/constants.js stays next to setSimProjectileSpeeds.
leiming2333