fix: prevent double-tap race conditions and poll leaks in JoinBoutPage

- Don't reset isJoining flags on successful navigation (component unmounts)
- Add onBeforeRouteLeave guard to clean up polling and rate limit timers
- Use handleError with rate limit countdown for all error paths

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

frontend/src/pages/JoinBoutPage.vue

@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import { ref, onMounted, onUnmounted } from 'vue'
-import { useRouter } from 'vue-router'
+import { useRouter, onBeforeRouteLeave } from 'vue-router'
 import { useNostr } from '../composables/useNostr'
 import { useWallet } from '../composables/useWallet'
 import SpritePreview from '../components/SpritePreview.vue'
@@ -21,6 +21,8 @@ const step = ref<string>('login')
 const isHumanMode = ref(false)
 const selectedHumanSeed = ref('baby_fighter_1')
 const error = ref('')
+const rateLimitCountdown = ref(0)
+let rateLimitTimer: ReturnType<typeof setInterval> | null = null
 const isJoining = ref(false)
 const isJoiningRanked = ref(false)
 const isJoiningPractice = ref(false)
@@ -99,6 +101,32 @@ const archetypeList = [
   { id: 'snail', label: 'SNAIL', desc: 'Slow and steady' },
 ]
 
+/** Detect rate limit errors and start a visible countdown */
+function handleError(e: unknown, fallback: string) {
+  const msg = e instanceof Error ? e.message : fallback
+  error.value = msg
+  // Parse "Slow down" with retry seconds from the error message or check for countdown pattern
+  if (msg.toLowerCase().includes('too many requests') || msg.toLowerCase().includes('slow down')) {
+    startRateLimitTimer(msg)
+  }
+}
+
+function startRateLimitTimer(msg: string) {
+  // Try to extract seconds from response (our API returns retryAfterSec)
+  const match = msg.match(/(\d+)\s*s/)
+  let seconds = match ? parseInt(match[1]) : 30
+  if (seconds <= 0 || seconds > 3600) seconds = 30
+  rateLimitCountdown.value = seconds
+  if (rateLimitTimer) clearInterval(rateLimitTimer)
+  rateLimitTimer = setInterval(() => {
+    rateLimitCountdown.value--
+    if (rateLimitCountdown.value <= 0) {
+      if (rateLimitTimer) { clearInterval(rateLimitTimer); rateLimitTimer = null }
+      error.value = ''
+    }
+  }, 1000)
+}
+
 onMounted(() => {
   // If already logged in with a bot, go straight to ready
   if (isLoggedIn.value) {
@@ -108,8 +136,14 @@ onMounted(() => {
   pollHandle = setInterval(pollQueue, 3000)
 })
 
+onBeforeRouteLeave(() => {
+  if (pollHandle) { clearInterval(pollHandle); pollHandle = null }
+  if (rateLimitTimer) { clearInterval(rateLimitTimer); rateLimitTimer = null }
+})
+
 onUnmounted(() => {
   if (pollHandle) clearInterval(pollHandle)
+  if (rateLimitTimer) { clearInterval(rateLimitTimer); rateLimitTimer = null }
 })
 
 async function pollQueue() {
@@ -143,7 +177,7 @@ async function handleLogin() {
       step.value = 'choose-mode'
     }
   } catch (e) {
-    error.value = e instanceof Error ? e.message : 'Login failed.'
+    handleError(e, 'Login failed.')
   }
 }
 
@@ -166,7 +200,7 @@ async function handleNsecBackupDone() {
       step.value = 'choose-mode'
     }
   } catch (e) {
-    error.value = e instanceof Error ? e.message : 'Login failed.'
+    handleError(e, 'Login failed.')
   }
 }
 
@@ -209,7 +243,7 @@ async function handleNsecLogin() {
       step.value = 'choose-mode'
     }
   } catch (e) {
-    error.value = e instanceof Error ? e.message : 'Login failed.'
+    handleError(e, 'Login failed.')
   }
 }
 
@@ -322,7 +356,7 @@ async function registerHumanFighter() {
     await registerHuman(humanName.value.trim(), selectedHumanSeed.value)
     step.value = 'ready'
   } catch (e) {
-    error.value = e instanceof Error ? e.message : 'Registration failed.'
+    handleError(e, 'Registration failed.')
   }
 }
 
@@ -344,7 +378,7 @@ async function confirmWebhook() {
     await registerBot(botName.value.trim(), url, selectedArchetype.value)
     step.value = 'ready'
   } catch (e) {
-    error.value = e instanceof Error ? e.message : 'Registration failed.'
+    handleError(e, 'Registration failed.')
   }
 }
 
@@ -357,9 +391,11 @@ async function fight() {
     if (res.ok) {
       const data = await res.json()
       router.push(`/arena/${data.fightId}`)
+      return // Don't reset flag — navigation will unmount component
     } else {
       const data = await res.json()
-      error.value = data.error || 'Failed to join.'
+      const msg = data.retryAfterSec ? `${data.error} (${data.retryAfterSec}s)` : (data.error || 'Failed to join.')
+      handleError(new Error(msg), 'Failed to join.')
     }
   } catch {
     error.value = 'Network error.'
@@ -381,12 +417,14 @@ async function fightRanked() {
     if (res.ok) {
       const data = await res.json()
       router.push(`/arena/${data.fightId}`)
+      return // Don't reset flag — navigation will unmount component
     } else {
       const data = await res.json()
-      error.value = data.error || 'Ranked match failed.'
+      const msg = data.retryAfterSec ? `${data.error} (${data.retryAfterSec}s)` : (data.error || 'Ranked match failed.')
+      handleError(new Error(msg), 'Ranked match failed.')
     }
   } catch (err) {
-    error.value = err instanceof Error ? err.message : 'Ranked fight error.'
+    handleError(err, 'Ranked fight error.')
   }
   isJoiningRanked.value = false
 }
@@ -402,9 +440,11 @@ async function practice() {
     if (res.ok) {
       const data = await res.json()
       router.push(`/arena/${data.fightId}`)
+      return // Don't reset flag — navigation will unmount component
     } else {
       const data = await res.json()
-      error.value = data.error || 'Failed to start practice fight.'
+      const msg = data.retryAfterSec ? `${data.error} (${data.retryAfterSec}s)` : (data.error || 'Failed to start practice fight.')
+      handleError(new Error(msg), 'Practice fight failed.')
     }
   } catch {
     error.value = 'Network error.'
@@ -1104,6 +1144,12 @@ function handleSignOut() {
       <!-- Error display -->
       <div v-if="error" class="mt-4 p-3 border-2 border-ko/30 bg-ko/5 text-center">
         <p class="font-mono text-xs text-ko">{{ error }}</p>
+        <div v-if="rateLimitCountdown > 0" class="mt-2 flex items-center justify-center gap-2">
+          <div class="w-4 h-4 border-2 border-neon-purple/60 border-t-neon-purple rounded-full animate-spin" />
+          <p class="font-display font-bold text-sm text-neon-purple tracking-wider">
+            {{ rateLimitCountdown }}s
+          </p>
+        </div>
       </div>
     </div>
   </div>