Every flourish gets its own file, and a workshop to watch them in

The effects move out of Board.svelte into src/fx-sprites/ — one
component per flourish, markup and animation CSS together, so editing
the fireball means opening Fireball.svelte and nothing else. A
registry (index.ts) maps kind to sprite; Board renders through it.
The event mapping stays in fx.ts.

And a viewer: /?fx opens the Flourish Workshop — every sprite on a
labeled parchment tile, replaying on a 2.2-second beat. Under the dev
server, editing any sprite file hot-reloads the gallery mid-loop.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/web/src/fx-sprites/ChaosSwirl.svelte

@@ -0,0 +1,29 @@
+<script lang="ts">
+  import type { FxOf } from "../fx";
+  import { center } from "./geom";
+  let { fx }: { fx: FxOf<"chaos-swirl"> } = $props();
+  const c = $derived(center(fx.at));
+</script>
+
+<g class="chaos" style={`transform-origin: ${c.x}px ${c.y}px`}>
+  <circle cx={c.x} cy={c.y} r="30" />
+  <circle cx={c.x} cy={c.y} r="55" class="mid" />
+  <circle cx={c.x} cy={c.y} r="80" class="outer" />
+</g>
+
+<style>
+  .chaos circle {
+    fill: none;
+    stroke: #b48ae0;
+    stroke-width: 4;
+    stroke-dasharray: 30 22;
+  }
+  .chaos .mid { stroke: #8a5fc0; stroke-dasharray: 44 30; }
+  .chaos .outer { stroke: #e2c8ff; stroke-dasharray: 60 40; }
+  .chaos { animation: chaos-spin 1.4s ease-in-out forwards; }
+  @keyframes chaos-spin {
+    0% { opacity: 0; transform: rotate(0deg) scale(0.6); }
+    20% { opacity: 1; }
+    100% { opacity: 0; transform: rotate(200deg) scale(1.5); }
+  }
+</style>