fix: replace silent error swallowing with console.warn and user-facing error messages

All empty catch blocks across 8 Vue pages now log warnings. User-initiated
actions (fight, matchmake) also surface errors in the UI via fightError/loadError refs.

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

frontend/src/pages/ArenaPage.vue

@@ -53,7 +53,9 @@ async function triggerFight() {
       const data = await res.json()
       router.push(`/arena/${data.fightId}`)
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[Arena] triggerFight failed:', err)
+  }
   isMocking.value = false
 }
 

frontend/src/pages/BotProfilePage.vue

@@ -77,6 +77,8 @@ const waitingFighters = ref<QueueEntry[]>([])
 let pollHandle: ReturnType<typeof setInterval> | null = null
 
 const isOwner = ref(false)
+const loadError = ref('')
+const fightError = ref('')
 const showCustomize = ref(false)
 const isSaving = ref(false)
 const custError = ref('')
@@ -207,7 +209,11 @@ onMounted(async () => {
   try {
     const res = await fetch(`/api/bots/${encodeURIComponent(botName)}/stats`)
     if (res.ok) stats.value = await res.json()
-  } catch { /* */ }
+    else loadError.value = `Failed to load bot (${res.status})`
+  } catch (err) {
+    loadError.value = 'Network error loading bot profile'
+    console.warn('[BotProfile] load failed:', err)
+  }
   isLoading.value = false
 
   // Check ownership
@@ -229,32 +235,46 @@ async function pollQueue() {
       const data = await res.json()
       waitingFighters.value = data.queue || []
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[BotProfile] queue poll failed:', err)
+  }
 }
 
 async function instantFight() {
   if (!stats.value || isJoining.value) return
   isJoining.value = true
+  fightError.value = ''
   try {
     const res = await fetch(`/api/queue/join/${stats.value.id}`, { method: 'POST' })
     if (res.ok) {
       const data = await res.json()
       router.push(`/arena/${data.fightId}`)
+    } else {
+      fightError.value = `Matchmaking failed (${res.status})`
     }
-  } catch { /* */ }
+  } catch (err) {
+    fightError.value = 'Network error starting fight'
+    console.warn('[BotProfile] instant fight failed:', err)
+  }
   isJoining.value = false
 }
 
 async function fightSpecific(opponentBotId: string) {
   if (!stats.value || isJoining.value) return
   isJoining.value = true
+  fightError.value = ''
   try {
     const res = await fetch(`/api/fights/matchmake/${stats.value.id}`, { method: 'POST' })
     if (res.ok) {
       const data = await res.json()
       router.push(`/arena/${data.fightId}`)
+    } else {
+      fightError.value = `Matchmaking failed (${res.status})`
     }
-  } catch { /* */ }
+  } catch (err) {
+    fightError.value = 'Network error starting fight'
+    console.warn('[BotProfile] fight specific failed:', err)
+  }
   isJoining.value = false
 }
 
@@ -275,7 +295,7 @@ const tierClass = (t: number) => `tier-${t}`
       </div>
 
       <div v-else-if="!stats" class="flex-1 flex items-center justify-center">
-        <p class="font-display text-text-muted">Bot not found.</p>
+        <p class="font-display text-text-muted">{{ loadError || 'Bot not found.' }}</p>
       </div>
 
       <template v-else>
@@ -426,6 +446,8 @@ const tierClass = (t: number) => `tier-${t}`
               </button>
             </div>
 
+            <p v-if="fightError" class="font-mono text-[10px] text-neon-pink mt-2">{{ fightError }}</p>
+
             <!-- Choose your fight panel -->
             <div v-if="showChoose" class="mt-3 border border-border bg-surface-raised/50 p-3">
               <p class="font-display text-[10px] font-bold text-text-muted tracking-[0.15em] mb-2">

frontend/src/pages/FightPage.vue

@@ -192,7 +192,9 @@ async function loadFight(): Promise<string | null> {
       }
       return data.status
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[FightPage] loadFight failed:', err)
+  }
   return null
 }
 
@@ -254,7 +256,9 @@ async function pollForChallenge() {
     } else if (humanSubmitted.value) {
       humanChallenge.value = null
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[FightPage] pollForChallenge failed:', err)
+  }
 }
 
 function startTimer() {
@@ -287,7 +291,9 @@ async function submitHumanAnswer() {
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ answer: humanAnswer.value.trim() }),
     })
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[FightPage] submitHumanAnswer failed:', err)
+  }
 }
 
 // --- Live scene management ---
@@ -350,7 +356,9 @@ function connectSSE() {
         color: 'neon-green',
       })
       scrollLiveLog()
-    } catch { /* */ }
+    } catch (err) {
+      console.warn('[FightPage] SSE round_start parse failed:', err)
+    }
   })
 
   eventSource.addEventListener('human_challenge', async (e) => {
@@ -377,19 +385,25 @@ function connectSSE() {
       } else {
         applyChallenge(sseData)
       }
-    } catch { /* */ }
+    } catch (err) {
+      console.warn('[FightPage] SSE human_challenge failed:', err)
+    }
   })
 
   eventSource.addEventListener('round_end', (e) => {
     try {
       handleRoundEnd(JSON.parse(e.data))
-    } catch { /* */ }
+    } catch (err) {
+      console.warn('[FightPage] SSE round_end failed:', err)
+    }
   })
 
   eventSource.addEventListener('fight_end', (e) => {
     try {
       handleFightEnd(JSON.parse(e.data))
-    } catch { /* */ }
+    } catch (err) {
+      console.warn('[FightPage] SSE fight_end failed:', err)
+    }
   })
 
   let sseRetries = 0
@@ -492,7 +506,9 @@ async function handleRoundEnd(data: any) {
         botAScore: result.botAScore || 0,
         botBScore: result.botBScore || 0,
       })
-    } catch { /* */ }
+    } catch (err) {
+      console.warn('[FightPage] playRound animation failed:', err)
+    }
 
     if (aWon || bWon) {
       await liveScene.playTaunt(aWon ? 'a' : 'b')
@@ -679,8 +695,13 @@ async function fightAgain(botId: string) {
         await nextTick()
         if (liveFightData.value) await initLiveScene()
       }
+    } else {
+      fightError.value = `Failed to start fight (${res.status})`
     }
-  } catch { /* */ }
+  } catch (err) {
+    fightError.value = 'Network error starting fight'
+    console.warn('[FightPage] fightAgain failed:', err)
+  }
   isRequeueing.value = false
 }
 
@@ -699,8 +720,13 @@ async function matchmake(botId: string) {
       fightError.value = ''
       window.history.replaceState({}, '', `/arena/${data.fightId}`)
       startPolling()
+    } else {
+      fightError.value = `Matchmaking failed (${res.status})`
     }
-  } catch { /* */ }
+  } catch (err) {
+    fightError.value = 'Network error during matchmaking'
+    console.warn('[FightPage] matchmake failed:', err)
+  }
   isRequeueing.value = false
 }
 

frontend/src/pages/HomePage.vue

@@ -304,7 +304,9 @@ onMounted(async () => {
       const data = await res.json()
       recentFights.value = data.slice(0, 4)
     }
-  } catch { /* server not running */ }
+  } catch (err) {
+    console.warn('[Home] load fights failed:', err)
+  }
 })
 
 onUnmounted(() => {

frontend/src/pages/HumanFightPage.vue

@@ -171,7 +171,9 @@ async function loadFight() {
         enemyHp.value = amSideA.value ? data.botBHp : data.botAHp
       }
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[HumanFight] poll failed:', err)
+  }
 }
 
 function watchReplay() {

frontend/src/pages/JoinBoutPage.vue

@@ -101,7 +101,9 @@ async function pollQueue() {
       const data = await res.json()
       queueCount.value = data.waiting
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[JoinBout] queue poll failed:', err)
+  }
 }
 
 async function handleLogin() {

frontend/src/pages/LeaderboardPage.vue

@@ -24,7 +24,9 @@ onMounted(async () => {
       const data = await res.json()
       bots.value = data.sort((a: Bot, b: Bot) => b.eloRating - a.eloRating)
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[Leaderboard] load failed:', err)
+  }
   isLoading.value = false
 })
 

frontend/src/pages/SchedulePage.vue

@@ -21,7 +21,9 @@ onMounted(async () => {
       const data = await res.json()
       bots.value = data.sort((a: Bot, b: Bot) => b.eloRating - a.eloRating)
     }
-  } catch { /* */ }
+  } catch (err) {
+    console.warn('[Schedule] load bots failed:', err)
+  }
   isLoading.value = false
 })