feat: victory celebration animations

Normal wins: winner flex pose with camera flash bursts + confetti rain.
Upset wins (100+ Elo underdog): dramatic zoom on winner with golden
flash. Upset tag shown on win overlay. Wired into FightViewer after
KO/Perfect sequence.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/FightViewer.vue

@@ -587,12 +587,19 @@ async function _doReplay() {
         await sleep(300) // let fatality voice finish
       }
 
+      // Victory celebration — detect upsets (winner had lower Elo)
+      const winnerElo = winningSide === 'a' ? (props.fight.botA?.eloRating ?? 1200) : (props.fight.botB?.eloRating ?? 1200)
+      const loserElo = winningSide === 'a' ? (props.fight.botB?.eloRating ?? 1200) : (props.fight.botA?.eloRating ?? 1200)
+      const isUpset = winnerElo < loserElo - 100
+      await scene.playVictoryCelebration(winningSide, isUpset)
+
       glitching.value = true
       sfxApplause()
       sfxCrowdCheer()
       await sleep(200)
       glitching.value = false
-      await showOverlay(`${winnerName} WINS!`, '#00f0ff', 1800)
+      const upsetTag = isUpset ? ' UPSET!' : ''
+      await showOverlay(`${winnerName} WINS!${upsetTag}`, isUpset ? '#ff6600' : '#00f0ff', 1800)
 
       logItems.value.push(
         { type: 'divider', round: 99, text: '', color: '' },

frontend/src/game/FightScene.ts

@@ -12118,6 +12118,48 @@ export async function createFightScene(config: FightSceneConfig) {
       await k.wait(0.7)
     },
 
+    async playVictoryCelebration(winningSide: 'a' | 'b', isUpset: boolean) {
+      const winner = k.get(winningSide === 'a' ? 'fighterA' : 'fighterB')[0] as Fighter
+      const loser = k.get(winningSide === 'a' ? 'fighterB' : 'fighterA')[0] as Fighter
+      if (!winner) return
+
+      if (isUpset) {
+        // UPSET: Dramatic zoom on winner + shocked gasp
+        const origSX = winner.scale.x
+        const origSY = winner.scale.y
+        sfxZoomWhoosh()
+        await Promise.all([
+          k.tween(Math.abs(origSX), 4, 0.25, (v: number) => { winner.scale.x = origSX > 0 ? v : -v; winner.scale.y = v }, k.easings.easeOutQuad),
+          k.tween(winner.pos.x, W / 2, 0.25, (v: number) => { winner.pos.x = v }, k.easings.easeOutQuad),
+        ])
+        screenFlash('#ffe14d', 0.15)
+        k.shake(8)
+        await k.wait(0.6)
+        // Zoom back
+        await Promise.all([
+          k.tween(winner.scale.y, Math.abs(origSY), 0.2, (v: number) => { winner.scale.x = origSX > 0 ? v : -v; winner.scale.y = v }, k.easings.easeInQuad),
+          k.tween(winner.pos.x, winningSide === 'a' ? HOME_A : HOME_B, 0.2, (v: number) => { winner.pos.x = v }, k.easings.easeInQuad),
+        ])
+      } else {
+        // NORMAL: Winner flex pose with camera flash
+        winner.play('win')
+        await k.wait(0.3)
+        screenFlash('#ffffff', 0.08)
+        sfxSpecial()
+        await k.wait(0.15)
+        screenFlash('#ffffff', 0.06)
+        await k.wait(0.15)
+        screenFlash('#ffffff', 0.04)
+        // Confetti shower
+        for (let i = 0; i < 20; i++) {
+          const cx = Math.random() * W
+          const confetti = k.add([k.rect(4, 4), k.pos(cx, -5), k.color(safeColor(k, ['#ff2d7b', '#00f0ff', '#ffe14d', '#39ff14', '#b83dff', '#ff6600'][i % 6])), k.opacity(0.9), k.z(20), k.rotate(Math.random() * 360)])
+          k.tween(confetti.pos.y, GROUND_Y + 10, 0.8 + Math.random() * 0.5, (v: number) => { confetti.pos.y = v; confetti.angle += 180 * k.dt() }).then(() => confetti.destroy())
+        }
+      }
+      await k.wait(0.4)
+    },
+
     startMusic() { startMusic() },
     stopMusic() { stopMusic() },