fix: polling bots play practice fights as human players in browser

Polling bots have no external script running during practice mode,
so the poll would time out giving empty answers. Now overrides the
webhook URL to human.local so the browser UI handles challenges.

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

server/src/routes/fights.ts

@@ -11,7 +11,7 @@ import { runFight, runFightAsync, isInFight, getActiveFightId } from '../engine/
 import { fightEvents } from '../engine/events.js'
 import { botRateLimit } from '../middleware/rate-limit.js'
 import { getPendingChallenge, getPendingAnswers, submitHumanResponse } from '../engine/human-responses.js'
-import { getPendingPollChallenge, submitPollResponse } from '../engine/poll-responses.js'
+import { getPendingPollChallenge, submitPollResponse, isPollingBot } from '../engine/poll-responses.js'
 import { authenticateBot } from '../middleware/bot-auth.js'
 import { checkAnswer } from '../engine/answers.js'
 
@@ -310,7 +310,9 @@ fightsRouter.post('/practice/:botId', botRateLimit(10_000), async (c) => {
 
   let fightId: string
   try {
-    fightId = await runFightAsync(botId, opponent.id, 'free')
+    // Polling bots play practice as human players (answer in browser)
+    const overrides = isPollingBot(bot.webhookUrl) ? { botAWebhookUrl: 'http://human.local/' } : undefined
+    fightId = await runFightAsync(botId, opponent.id, 'free', overrides)
   } catch (err) {
     const msg = err instanceof Error ? err.message : 'Fight failed to start'
     return c.json({ error: msg }, 400)