diff --git a/src/lib/components/chrome/SplashScreen.svelte b/src/lib/components/chrome/SplashScreen.svelte
index 31bd9be..fad48ec 100644
--- a/src/lib/components/chrome/SplashScreen.svelte
+++ b/src/lib/components/chrome/SplashScreen.svelte
@@ -1,9 +1,46 @@
+<script module lang="ts">
+  function getLiveSet(): Set<HTMLCanvasElement> {
+    const g = window as any
+    if (!g.__splashCanvasSet) g.__splashCanvasSet = new Set<HTMLCanvasElement>()
+    return g.__splashCanvasSet as Set<HTMLCanvasElement>
+  }
+
+  function pruneSet(set: Set<HTMLCanvasElement>) {
+    for (const el of set) if (!el.isConnected) set.delete(el)
+  }
+
+  export function splashDevRegister(el: HTMLCanvasElement) {
+    const set = getLiveSet()
+    pruneSet(set)
+    set.add(el)
+  }
+
+  export function splashDevUnregister(el: HTMLCanvasElement) {
+    const set = getLiveSet()
+    set.delete(el)
+    pruneSet(set)
+  }
+
+  export function splashDevLiveCount(): number {
+    const set = getLiveSet()
+    pruneSet(set)
+    return set.size
+  }
+
+  export function splashDevNextMount(): number {
+    const g = window as any
+    g.__splashTotalMounts = (g.__splashTotalMounts ?? 0) + 1
+    return g.__splashTotalMounts as number
+  }
+</script>
+
 <script lang="ts">
   import { onMount } from 'svelte'
   import logoUrl     from '$lib/assets/moku-icon-splash.svg'
   import { platformService } from '$lib/platform-service'
 
   const isTauri = platformService.platform === 'tauri'
+  const isDev   = import.meta.env.DEV
 
   interface Props {
     mode?:          'loading' | 'idle' | 'locked'
@@ -80,7 +117,7 @@
 
   $effect(() => {
     if (mode === 'loading' && !failed && !notConfigured && !ringFull) {
-      if (!isTauri) return  // no ring animation on web; probe outcome drives exit
+      if (!isTauri) return
       animStart = null
       animPhase = 1
       animFrame = requestAnimationFrame(animateRing)
@@ -280,23 +317,87 @@
     }
   }
 
+  interface DevMetrics {
+    totalMounts:  number
+    resizeCount:  number
+    stampCount:   number
+    mountedAt:    number
+    lastResizeAt: number | null
+  }
+
+  let devMetrics   = $state<DevMetrics | null>(null)
+  let uptimeSecs   = $state(0)
+  let devLiveCount = $state(0)
+
+  $effect(() => {
+    if (!isDev || mode !== 'idle' || !devMetrics) return
+    const start = Date.now()
+    const iv = setInterval(() => { uptimeSecs = Math.floor((Date.now() - start) / 1000) }, 1000)
+    return () => clearInterval(iv)
+  })
+
+  function fmtUptime(s: number): string {
+    if (s < 60) return `${s}s`
+    return `${Math.floor(s / 60)}m ${s % 60}s`
+  }
+
+  function fmtAgo(ts: number | null): string {
+    if (ts === null) return '—'
+    const s = Math.floor((Date.now() - ts) / 1000)
+    if (s < 60) return `${s}s ago`
+    return `${Math.floor(s / 60)}m ago`
+  }
+
   function mountCanvas(el: HTMLCanvasElement) {
     const ctx = el.getContext('2d')!
     let live: RenderState | null = null
     let lastLogW = 0, lastLogH = 0, lastScale = 0, buildGen = 0
 
+    if (isDev && mode === 'idle') {
+      splashDevRegister(el)
+      devLiveCount = splashDevLiveCount()
+      uptimeSecs   = 0
+      devMetrics   = {
+        totalMounts:  splashDevNextMount(),
+        resizeCount:  0,
+        stampCount:   0,
+        mountedAt:    Date.now(),
+        lastResizeAt: null,
+      }
+    }
+
+    function cleanup() {
+      if (live) {
+        live.stamps.forEach(c => { c.width = 0; c.height = 0 })
+        live.vignette.width = 0
+        live.vignette.height = 0
+        live = null
+      }
+      ctx.clearRect(0, 0, el.width, el.height)
+    }
+
     function applySize(logW: number, logH: number, scale: number) {
       const gen = ++buildGen
       if (logW <= 0 || logH <= 0) return
       if (logW === lastLogW && logH === lastLogH && scale === lastScale) return
       lastLogW = logW; lastLogH = logH; lastScale = scale
-      if (live) cleanup()  // release old offscreen canvases before rebuilding at new size
+      if (live) cleanup()
       const built  = buildCards(logW, logH)
       const stamps = built.cards.map(c => buildStamp(c, scale))
       const vig    = buildVignette(logW, logH, scale)
       el.width  = Math.round(logW * scale)
       el.height = Math.round(logH * scale)
-      if (gen === buildGen) live = { cards: built.cards, trigs: built.trigs, stamps, vignette: vig, CW: el.width, CH: el.height, scale }
+      if (gen === buildGen) {
+        live = { cards: built.cards, trigs: built.trigs, stamps, vignette: vig, CW: el.width, CH: el.height, scale }
+        if (isDev && mode === 'idle' && devMetrics) {
+          devMetrics = {
+            ...devMetrics,
+            resizeCount:  devMetrics.resizeCount + 1,
+            stampCount:   stamps.length,
+            lastResizeAt: Date.now(),
+          }
+        }
+      }
     }
 
     let extraCleanup: (() => void) | undefined
@@ -340,20 +441,6 @@
     function resume() { if (!paused) return; paused = false; raf = requestAnimationFrame(frame) }
     function onVis()  { document.hidden ? pause() : resume() }
 
-    // clears all canvas contexts and nulls live state so the GC can collect the offscreen bitmaps
-    function cleanup() {
-      if (live) {
-        live.stamps.forEach(canvas => {
-          const c = canvas.getContext('2d')
-          if (c) c.clearRect(0, 0, canvas.width, canvas.height)
-        })
-        const vigCtx = live.vignette.getContext('2d')
-        if (vigCtx) vigCtx.clearRect(0, 0, live.vignette.width, live.vignette.height)
-      }
-      ctx.clearRect(0, 0, el.width, el.height)
-      live = null
-    }
-
     document.addEventListener('visibilitychange', onVis)
     raf = requestAnimationFrame(frame)
     return () => {
@@ -361,6 +448,10 @@
       cleanup()
       extraCleanup?.()
       document.removeEventListener('visibilitychange', onVis)
+      if (isDev && mode === 'idle') {
+        splashDevUnregister(el)
+        devLiveCount = splashDevLiveCount()
+      }
     }
   }
 </script>
@@ -373,6 +464,20 @@
     {/if}
   {/if}
 
+  {#if isDev && mode === 'idle' && devMetrics}
+    <div class="dev-overlay">
+      <span class="dev-title">canvas · idle splash</span>
+      <div class="dev-grid">
+        <span class="dev-k">live</span>          <span class="dev-v" class:dev-warn={devLiveCount > 1}>{devLiveCount}</span>
+        <span class="dev-k">total mounts</span>  <span class="dev-v">{devMetrics.totalMounts}</span>
+        <span class="dev-k">stamps</span>        <span class="dev-v">{devMetrics.stampCount}</span>
+        <span class="dev-k">resizes</span>       <span class="dev-v">{devMetrics.resizeCount}</span>
+        <span class="dev-k">uptime</span>        <span class="dev-v">{fmtUptime(uptimeSecs)}</span>
+        <span class="dev-k">last resize</span>   <span class="dev-v">{fmtAgo(devMetrics.lastResizeAt)}</span>
+      </div>
+    </div>
+  {/if}
+
   {#if mode === 'idle'}
     <div style="z-index:1;display:flex;flex-direction:column;align-items:center">
       <div style="position:relative;width:{logoIdleSize}px;height:{logoIdleSize}px;margin-bottom:32px">
@@ -465,4 +570,11 @@
   .err-btn:hover { border-color:var(--border-strong); color:var(--text-secondary); }
   .err-btn--primary       { border-color:var(--accent-dim); color:var(--accent-fg); background:var(--accent-muted); }
   .err-btn--primary:hover { border-color:var(--accent); color:var(--accent-bright); }
+
+  .dev-overlay { position:absolute; top:12px; left:12px; z-index:10; background:rgba(0,0,0,0.72); border:1px solid rgba(255,255,255,0.10); border-radius:6px; padding:8px 10px; pointer-events:none; backdrop-filter:blur(6px); }
+  .dev-title   { display:block; font-family:var(--font-ui); font-size:9px; letter-spacing:0.14em; text-transform:uppercase; color:var(--accent); margin-bottom:6px; }
+  .dev-grid    { display:grid; grid-template-columns:auto auto; column-gap:12px; row-gap:2px; }
+  .dev-k       { font-family:var(--font-ui); font-size:10px; color:var(--text-faint); white-space:nowrap; }
+  .dev-v       { font-family:var(--font-ui); font-size:10px; color:var(--text-secondary); text-align:right; white-space:nowrap; }
+  .dev-warn    { color:#f87171; }
 </style>
\ No newline at end of file
diff --git a/src/lib/components/settings/sections/DevToolsSettings.svelte b/src/lib/components/settings/sections/DevToolsSettings.svelte
index 260b50a..9733bbe 100644
--- a/src/lib/components/settings/sections/DevToolsSettings.svelte
+++ b/src/lib/components/settings/sections/DevToolsSettings.svelte
@@ -102,6 +102,7 @@
   }
 
   function triggerSplash() {
+    if (appState.idleSplash) return
     splashTriggered = true
     setTimeout(() => splashTriggered = false, 200)
     appState.idleSplash = true
diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
index 6163767..3db14b5 100644
--- a/src/routes/+layout.svelte
+++ b/src/routes/+layout.svelte
@@ -7,7 +7,7 @@
   import { settingsState, loadSettingsIntoState, updateSettings }       from '$lib/state/settings.svelte'
   import { applyTheme, mountSystemThemeSync }                           from '$lib/core/theme'
   import { platformService }                                            from '$lib/platform-service'
-  import { initRpc, setIdle, destroyRpc }                                from '$lib/core/discord'
+  import * as discord                                                   from '$lib/core/discord'
   import SplashScreen                                                   from '$lib/components/chrome/SplashScreen.svelte'
   import AuthGate                                                       from '$lib/components/chrome/AuthGate.svelte'
   import Sidebar                                                        from '$lib/components/chrome/Sidebar.svelte'
@@ -24,7 +24,6 @@
 
   const POLL_MS = 1500
   let pollTimer: ReturnType<typeof setTimeout> | null = null
-  let idleTimer: ReturnType<typeof setTimeout> | null = null
   let polling = false
 
   async function pollLoop() {
@@ -35,13 +34,12 @@
 
   const isTauri = typeof window !== 'undefined' && '__TAURI_INTERNALS__' in window
 
-  let _splashDismissed = $state(false)
-  let bypassed         = $state(false)
-  let themeEditorOpen  = $state(false)
-  let themeEditorId    = $state<string | null>(null)
+  let splashDismissed = $state(false)
+  let themeEditorOpen = $state(false)
+  let themeEditorId   = $state<string | null>(null)
 
   const splashVisible = $derived(
-    !_splashDismissed ||
+    !splashDismissed ||
     appState.status === 'booting' ||
     appState.status === 'locked'  ||
     appState.status === 'error'   ||
@@ -49,17 +47,16 @@
   )
 
   const ringFull = $derived(appState.status === 'ready')
+  const showApp  = $derived(!splashVisible)
 
-  const showApp = $derived(
-    !splashVisible && (
-      appState.status === 'ready' ||
-      bypassed
-    )
-  )
-
-  function onSplashReady()  { _splashDismissed = true }
-  function onSplashUnlock() { appState.status = 'ready'; _splashDismissed = true }
-  function onSplashBypass() { bypassed = true; _splashDismissed = true }
+  function onSplashReady()  { splashDismissed = true }
+  function onSplashUnlock() { appState.status = 'ready'; splashDismissed = true }
+  function onSplashBypass() {
+    import('$lib/state/boot.svelte').then(({ bypassBoot }) => {
+      bypassBoot(appState.authMode ?? 'NONE', appState.authUser ?? '', appState.authPass ?? '')
+    })
+    splashDismissed = true
+  }
 
   const isReaderRoute       = $derived($page.url.pathname.startsWith('/reader'))
   const readerContainerized = $derived(settingsState.settings.readerContainerized ?? false)
@@ -108,24 +105,19 @@
       isTauri && settingsState.settings.autoStartServer ? 2000 : 100,
     )
 
-    let discordInitialized = false
     if (settingsState.settings.discordRpc) {
-      await initRpc()
-      await setIdle()
-      discordInitialized = true
+      await discord.initRpc()
+      await discord.setIdle()
     }
 
     polling = true
     pollLoop()
 
-    resetIdleTimer()
-
     return () => {
       polling = false
       if (pollTimer !== null) { clearTimeout(pollTimer); pollTimer = null }
-      if (idleTimer !== null) { clearTimeout(idleTimer); idleTimer = null }
-      if (discordInitialized) destroyRpc().catch(() => {})
-      platformService.destroy().catch(() => {})
+      discord.destroyRpc()
+      platformService.destroy()
     }
   })
 
@@ -147,49 +139,22 @@
   })
 
   $effect(() => {
-    if (appState.status === 'booting') _splashDismissed = false
+    if (appState.status === 'booting') splashDismissed = false
   })
 
-  $effect(() => {
-    if (appState.status === 'ready') resetIdleTimer()
-  })
+  let idleSplashLocked = false
 
-  $effect(() => {
-    if (appState.idleSplash && settingsState.settings.discordRpc) setIdle().catch(() => {})
-  })
-
-  $effect(() => {
-    if (appState.status !== 'ready') return
-    // capture phase so events from any component — including modals — reset the timer
-    const onActivity = () => resetIdleTimer()
-    document.addEventListener('mousemove',  onActivity, true)
-    document.addEventListener('keydown',    onActivity, true)
-    document.addEventListener('touchstart', onActivity, true)
-    // passive:true tells the browser it can render scroll frames without waiting for the handler
-    document.addEventListener('touchmove',  onActivity, { capture: true, passive: true })
-    document.addEventListener('wheel',      onActivity, { capture: true, passive: true })
-    document.addEventListener('click',      onActivity, true)
-    return () => {
-      document.removeEventListener('mousemove',  onActivity, true)
-      document.removeEventListener('keydown',    onActivity, true)
-      document.removeEventListener('touchstart', onActivity, true)
-      document.removeEventListener('touchmove',  onActivity, { capture: true })
-      document.removeEventListener('wheel',      onActivity, { capture: true })
-      document.removeEventListener('click',      onActivity, true)
-    }
-  })
-
-  function resetIdleTimer() {
-    if (idleTimer) { clearTimeout(idleTimer); idleTimer = null }
-    // 0 means "Never" — skip the timer entirely
-    const mins = settingsState.settings.idleTimeoutMin ?? 5
-    if (mins === 0) return
-    idleTimer = setTimeout(() => {
-      if (appState.status === 'ready') appState.idleSplash = true
-    }, mins * 60_000)
+  function showIdleSplash() {
+    if (idleSplashLocked || appState.idleSplash) return
+    appState.idleSplash = true
   }
 
-  function onIdleDismiss() { appState.idleSplash = false; resetIdleTimer() }
+  function onIdleDismiss() {
+    if (idleSplashLocked) return
+    idleSplashLocked = true
+    appState.idleSplash = false
+    setTimeout(() => { idleSplashLocked = false }, 400)
+  }
 
   function onSplashRetry() {
     import('$lib/state/boot.svelte').then(({ retryBoot }) => {
@@ -219,7 +184,7 @@
 {/if}
 
 {#if appState.idleSplash}
-  <SplashScreen mode="idle" onDismiss={onIdleDismiss} />
+  <SplashScreen mode="idle" showCards={settingsState.settings.splashCards ?? true} onDismiss={onIdleDismiss} />
 {/if}
 
 {#if showApp}