Flourishes: the spells become visible (branch only — not for the droplet yet)

A cosmetic effects layer on the board svg, fed by the same event
stream that writes the log. Fireballs streak and burst; waterbolts
arc and splash; lightning jags and flickers; teleports shimmer at
both ends; walls rise and fall in dust; stopped attacks flash a
golden shield; hits ring red; misses whiff; other attack spells
sparkle at the caster. Successive visuals from one command stagger by
a beat, everything self-expires, reduced-motion hides the layer
whole, and nothing here touches game state — the effects are mapped
from events in fx.ts and drawn in Board.svelte, online and hotseat
alike.

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

packages/web/src/net.svelte.ts

@@ -253,6 +253,8 @@ class Net {
   /** A catch-up reel delivered by the server. */
   /** The opening roll-off, shown once as the boards flip. */
   openingRolls = $state<{ rolls: Record<string, number[]>; first: string; players: string[] } | null>(null);
+  /** Board flourishes: the app hooks in to animate live event batches. */
+  onFx: ((events: GameEvent[]) => void) | null = null;
   catchUp = $state<{ seq: number; actor: string; events: GameEvent[]; view: GameView; chat?: { player: string; text: string }[] }[] | null>(null);
   private seen: Record<string, number> = loadSeen();
   /** Room whose live stream this connection has already shown once: states
@@ -342,6 +344,7 @@ class Net {
           break;
         case "events": {
           let talk = 0;
+          if (!msg.replayed) this.onFx?.(msg.events as GameEvent[]);
           for (const e of msg.events as GameEvent[]) {
             if (e.type === "tableTalk") talk++;
             if (e.type === "gameStarted" && !msg.replayed) {