diff --git a/apps/stage-pocket/src/components/DataGui/DualEndRange.vue b/apps/stage-pocket/src/components/DataGui/DualEndRange.vue
index 8466d1d27..741c0bc5e 100644
--- a/apps/stage-pocket/src/components/DataGui/DualEndRange.vue
+++ b/apps/stage-pocket/src/components/DataGui/DualEndRange.vue
@@ -73,7 +73,7 @@ const sortedValues = computed(() => {
 
 const sliderStyle = computed(() => {
   const sliderOffset = valueToPercent(sortedValues.value[0], props.min, props.max)
-  const sliderLeap = valueToPercent(sortedValues.value[sortedValues.value.length - 1], props.min, props.max) - sliderOffset
+  const sliderLeap = valueToPercent(sortedValues.value.at(-1), props.min, props.max) - sliderOffset
   return {
     left: `${sliderOffset}%`,
     width: `${sliderLeap}%`,
diff --git a/apps/stage-pocket/src/pages/devtools/background-removal.vue b/apps/stage-pocket/src/pages/devtools/background-removal.vue
index 2877391d0..66dbb3f14 100644
--- a/apps/stage-pocket/src/pages/devtools/background-removal.vue
+++ b/apps/stage-pocket/src/pages/devtools/background-removal.vue
@@ -170,7 +170,7 @@ function downloadAllImages() {
 
   doneItems.forEach((_, i) => {
     const index = imageItems.value.indexOf(doneItems[i])
-    setTimeout(() => downloadImage(index), i * 100)
+    setTimeout(downloadImage, i * 100, index)
   })
 }
 
diff --git a/apps/stage-tamagotchi/src/main/windows/widgets/index.ts b/apps/stage-tamagotchi/src/main/windows/widgets/index.ts
index 25ff283dc..c688df2a3 100644
--- a/apps/stage-tamagotchi/src/main/windows/widgets/index.ts
+++ b/apps/stage-tamagotchi/src/main/windows/widgets/index.ts
@@ -195,7 +195,7 @@ export function setupWidgetsWindowManager(params: {
     const record: WidgetRecord = { ...snapshot }
 
     if (snapshot.ttlMs > 0) {
-      record.timer = setTimeout(() => removeWidgetInternal(snapshot.id), snapshot.ttlMs)
+      record.timer = setTimeout(removeWidgetInternal, snapshot.ttlMs, snapshot.id)
     }
 
     widgetRecords.set(snapshot.id, record)
diff --git a/apps/stage-tamagotchi/src/renderer/pages/widgets.vue b/apps/stage-tamagotchi/src/renderer/pages/widgets.vue
index e42ae41b6..cab094644 100644
--- a/apps/stage-tamagotchi/src/renderer/pages/widgets.vue
+++ b/apps/stage-tamagotchi/src/renderer/pages/widgets.vue
@@ -65,7 +65,7 @@ function applySnapshot(snapshot: WidgetSnapshot) {
   }
 
   if (snapshot.ttlMs && snapshot.ttlMs > 0) {
-    ttlTimer = setTimeout(() => requestRemoval(snapshot.id), snapshot.ttlMs)
+    ttlTimer = setTimeout(requestRemoval, snapshot.ttlMs, snapshot.id)
   }
 }
 
diff --git a/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue b/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue
index b3652db24..473285f80 100644
--- a/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue
+++ b/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue
@@ -74,7 +74,7 @@ const routePoints = computed(() => {
     return [resolvedOrigin.value, resolvedDestination.value]
 
   const first = points[0]
-  const last = points[points.length - 1]
+  const last = points.at(-1)
   if (first.x !== resolvedOrigin.value.x || first.y !== resolvedOrigin.value.y)
     points.unshift(resolvedOrigin.value)
   if (last.x !== resolvedDestination.value.x || last.y !== resolvedDestination.value.y)
diff --git a/apps/stage-web/src/components/DataGui/DualEndRange.vue b/apps/stage-web/src/components/DataGui/DualEndRange.vue
index 8466d1d27..741c0bc5e 100644
--- a/apps/stage-web/src/components/DataGui/DualEndRange.vue
+++ b/apps/stage-web/src/components/DataGui/DualEndRange.vue
@@ -73,7 +73,7 @@ const sortedValues = computed(() => {
 
 const sliderStyle = computed(() => {
   const sliderOffset = valueToPercent(sortedValues.value[0], props.min, props.max)
-  const sliderLeap = valueToPercent(sortedValues.value[sortedValues.value.length - 1], props.min, props.max) - sliderOffset
+  const sliderLeap = valueToPercent(sortedValues.value.at(-1), props.min, props.max) - sliderOffset
   return {
     left: `${sliderOffset}%`,
     width: `${sliderLeap}%`,
diff --git a/apps/stage-web/src/pages/devtools/background-removal.vue b/apps/stage-web/src/pages/devtools/background-removal.vue
index 2877391d0..66dbb3f14 100644
--- a/apps/stage-web/src/pages/devtools/background-removal.vue
+++ b/apps/stage-web/src/pages/devtools/background-removal.vue
@@ -170,7 +170,7 @@ function downloadAllImages() {
 
   doneItems.forEach((_, i) => {
     const index = imageItems.value.indexOf(doneItems[i])
-    setTimeout(() => downloadImage(index), i * 100)
+    setTimeout(downloadImage, i * 100, index)
   })
 }
 
diff --git a/apps/stage-web/src/stores/devtools-lag.ts b/apps/stage-web/src/stores/devtools-lag.ts
index 8cda1733b..6acc5bc19 100644
--- a/apps/stage-web/src/stores/devtools-lag.ts
+++ b/apps/stage-web/src/stores/devtools-lag.ts
@@ -49,7 +49,7 @@ function calcStats(values: number[]) {
   const sorted = [...values].sort((a, b) => a - b)
   const idx = Math.max(0, Math.floor(0.95 * (sorted.length - 1)))
   const p95 = sorted[idx]
-  const latest = values[values.length - 1]
+  const latest = values.at(-1)
 
   return { avg, p95, latest }
 }
@@ -134,7 +134,7 @@ export const useDevtoolsLagStore = defineStore('devtoolsLag', () => {
     recordingStartedAt.value = performance.now()
     resetRecordingSamples()
 
-    recordingTimeout = setTimeout(() => stopRecording(), 60000)
+    recordingTimeout = setTimeout(stopRecording, 60000)
   }
 
   function stopRecording(): RecordingSnapshot | undefined {
diff --git a/docs/.vitepress/composables/outline.ts b/docs/.vitepress/composables/outline.ts
index bab4c8f26..0ebb5c844 100644
--- a/docs/.vitepress/composables/outline.ts
+++ b/docs/.vitepress/composables/outline.ts
@@ -192,7 +192,7 @@ export function useActiveAnchor(
 
     // page bottom - highlight last link
     if (isBottom) {
-      activateLink(headers[headers.length - 1]!.link)
+      activateLink(headers.at(-1)!.link)
       return
     }
 
diff --git a/docs/.vitepress/composables/sidebar.ts b/docs/.vitepress/composables/sidebar.ts
index 5bb693bb0..230a04a0a 100644
--- a/docs/.vitepress/composables/sidebar.ts
+++ b/docs/.vitepress/composables/sidebar.ts
@@ -288,7 +288,7 @@ export function hasActiveLink(
 }
 
 function addBase(items: SidebarItem[], _base?: string): SidebarItem[] {
-  return [...items].map((_item) => {
+  return Array.from(items, (_item) => {
     const item = { ..._item }
     const base = item.base || _base
     if (base && item.link)
diff --git a/docs/content/en/blog/DevLog-2025.08.01/CharacterMatcher.vue b/docs/content/en/blog/DevLog-2025.08.01/CharacterMatcher.vue
index 1d0313a4c..77f329fa3 100644
--- a/docs/content/en/blog/DevLog-2025.08.01/CharacterMatcher.vue
+++ b/docs/content/en/blog/DevLog-2025.08.01/CharacterMatcher.vue
@@ -15,7 +15,7 @@ function interpolate(characters: string[], initial?: Character[]) {
     return [
       ...chars,
       [
-        ...chars.length > 0 ? chars[chars.length - 1]! : [],
+        ...chars.length > 0 ? chars.at(-1)! : [],
         { value: c, variant: 'dotted' },
       ],
     ]
diff --git a/packages/stage-pages/src/pages/devtools/beat-sync.vue b/packages/stage-pages/src/pages/devtools/beat-sync.vue
index 553e12772..a9d52e542 100644
--- a/packages/stage-pages/src/pages/devtools/beat-sync.vue
+++ b/packages/stage-pages/src/pages/devtools/beat-sync.vue
@@ -165,7 +165,7 @@ function drawXY() {
   })
   ctx.stroke()
 
-  const head = trail.value[trail.value.length - 1]
+  const head = trail.value.at(-1)
   if (head) {
     ctx.beginPath()
     ctx.arc(centerX + head.x * scale.value, centerY - head.y * scale.value, 5, 0, Math.PI * 2)
diff --git a/packages/stage-pages/src/pages/settings/airi-card/components/CardCreationDialog.vue b/packages/stage-pages/src/pages/settings/airi-card/components/CardCreationDialog.vue
index 47175f493..fcb440392 100644
--- a/packages/stage-pages/src/pages/settings/airi-card/components/CardCreationDialog.vue
+++ b/packages/stage-pages/src/pages/settings/airi-card/components/CardCreationDialog.vue
@@ -191,7 +191,7 @@ const tabs: Tab[] = [
 const activeTab = computed({
   get: () => {
     // If current active tab is not in available tabs, reset to first tab
-    if (!tabs.find(tab => tab.id === activeTabId.value))
+    if (!tabs.some(tab => tab.id === activeTabId.value))
       return tabs[0]?.id || ''
     return activeTabId.value
   },
diff --git a/packages/stage-pages/src/pages/settings/airi-card/components/CardDetailDialog.vue b/packages/stage-pages/src/pages/settings/airi-card/components/CardDetailDialog.vue
index 6b2276725..4ad92823c 100644
--- a/packages/stage-pages/src/pages/settings/airi-card/components/CardDetailDialog.vue
+++ b/packages/stage-pages/src/pages/settings/airi-card/components/CardDetailDialog.vue
@@ -165,7 +165,7 @@ const tabs = computed<Tab[]>(() => {
 const activeTab = computed({
   get: () => {
     // If current active tab is not in available tabs, reset to first tab
-    if (!tabs.value.find(tab => tab.id === activeTabId.value))
+    if (!tabs.value.some(tab => tab.id === activeTabId.value))
       return tabs.value[0]?.id || ''
     return activeTabId.value
   },
diff --git a/packages/stage-pages/src/pages/settings/providers/chat/ollama.vue b/packages/stage-pages/src/pages/settings/providers/chat/ollama.vue
index 2c4303efc..a05c73bdb 100644
--- a/packages/stage-pages/src/pages/settings/providers/chat/ollama.vue
+++ b/packages/stage-pages/src/pages/settings/providers/chat/ollama.vue
@@ -77,7 +77,7 @@ function removeKeyValue(index: number, headers: { key: string, value: string }[]
 }
 
 watch(headers, (headers) => {
-  if (headers.length > 0 && (headers[headers.length - 1].key !== '' || headers[headers.length - 1].value !== '')) {
+  if (headers.length > 0 && (headers.at(-1).key !== '' || headers.at(-1).value !== '')) {
     headers.push({ key: '', value: '' })
   }
   if (!providers.value[providerId])
diff --git a/packages/stage-pages/src/pages/v2/settings/providers/edit/[providerId]/index.vue b/packages/stage-pages/src/pages/v2/settings/providers/edit/[providerId]/index.vue
index a14707fe2..7a048a7c3 100644
--- a/packages/stage-pages/src/pages/v2/settings/providers/edit/[providerId]/index.vue
+++ b/packages/stage-pages/src/pages/v2/settings/providers/edit/[providerId]/index.vue
@@ -160,7 +160,7 @@ function normalizeHeaderRows(headers: Record<string, string>) {
   if (rows.length === 0) {
     rows.push({ key: '', value: '' })
   }
-  else if (rows[rows.length - 1].key !== '' || rows[rows.length - 1].value !== '') {
+  else if (rows.at(-1).key !== '' || rows.at(-1).value !== '') {
     rows.push({ key: '', value: '' })
   }
   return rows
@@ -178,7 +178,7 @@ watch(providerConfigEdit, (config) => {
 watch(headerRows, (rows) => {
   if (isSyncingHeaders.value)
     return
-  const lastRow = rows[rows.length - 1]
+  const lastRow = rows.at(-1)
   if (!lastRow || lastRow.key.trim().length > 0 || lastRow.value.trim().length > 0) {
     headerRows.value = [...rows, { key: '', value: '' }]
     return
diff --git a/packages/stage-ui-live2d/src/composables/live2d/beat-sync.ts b/packages/stage-ui-live2d/src/composables/live2d/beat-sync.ts
index eb38393f5..03e97c936 100644
--- a/packages/stage-ui-live2d/src/composables/live2d/beat-sync.ts
+++ b/packages/stage-ui-live2d/src/composables/live2d/beat-sync.ts
@@ -137,10 +137,8 @@ export function createBeatSyncController(options: CreateBeatSyncControllerOption
       currentZ = baseAngles.value.z
     }
 
-    if (currentY == null)
-      currentY = baseAngles.value.y
-    if (currentZ == null)
-      currentZ = baseAngles.value.z
+    currentY ??= baseAngles.value.y
+    currentZ ??= baseAngles.value.z
 
     while (segments.value.length) {
       const segment = segments.value[0]
diff --git a/packages/stage-ui-live2d/src/utils/eye-motions.ts b/packages/stage-ui-live2d/src/utils/eye-motions.ts
index f31a7c3ff..e97a8a3fd 100644
--- a/packages/stage-ui-live2d/src/utils/eye-motions.ts
+++ b/packages/stage-ui-live2d/src/utils/eye-motions.ts
@@ -28,5 +28,5 @@ export function randomSaccadeInterval(): number {
       return EYE_SACCADE_INT_P[i][1] + Math.random() * EYE_SACCADE_INT_STEP
     }
   }
-  return EYE_SACCADE_INT_P[EYE_SACCADE_INT_P.length - 1][1] + Math.random() * EYE_SACCADE_INT_STEP
+  return EYE_SACCADE_INT_P.at(-1)[1] + Math.random() * EYE_SACCADE_INT_STEP
 }
diff --git a/packages/stage-ui-live2d/src/utils/live2d-zip-loader.ts b/packages/stage-ui-live2d/src/utils/live2d-zip-loader.ts
index d06066f3e..c7a41bde1 100644
--- a/packages/stage-ui-live2d/src/utils/live2d-zip-loader.ts
+++ b/packages/stage-ui-live2d/src/utils/live2d-zip-loader.ts
@@ -10,7 +10,7 @@ const defaultCreateSettings = ZipLoader.createSettings
 ZipLoader.createSettings = async (reader: JSZip) => {
   const filePaths = Object.keys(reader.files)
 
-  if (!filePaths.find(file => isSettingsFile(file))) {
+  if (!filePaths.some(file => isSettingsFile(file))) {
     return createFakeSettings(filePaths)
   }
 
diff --git a/packages/stage-ui-three/src/composables/shader/ibl.ts b/packages/stage-ui-three/src/composables/shader/ibl.ts
index cca11c90c..1417d41a3 100644
--- a/packages/stage-ui-three/src/composables/shader/ibl.ts
+++ b/packages/stage-ui-three/src/composables/shader/ibl.ts
@@ -122,7 +122,7 @@ export function injectDiffuseIBL(mat: THREE.ShaderMaterial) {
     }
 
     // uniforms
-    const emptySH = Array.from({ length: 9 }, () => new THREE.Vector3())
+    const emptySH = Array.from({ length: 9 }).fill(new THREE.Vector3())
     shader.uniforms.uNprEnvMode ||= { value: 0 }
     shader.uniforms.uEnvIntensity ||= { value: 0.0 }
     shader.uniforms.uSHCoeffs ||= { value: emptySH };
diff --git a/packages/stage-ui-three/src/composables/vrm/utils/eye-motions.ts b/packages/stage-ui-three/src/composables/vrm/utils/eye-motions.ts
index f31a7c3ff..e97a8a3fd 100644
--- a/packages/stage-ui-three/src/composables/vrm/utils/eye-motions.ts
+++ b/packages/stage-ui-three/src/composables/vrm/utils/eye-motions.ts
@@ -28,5 +28,5 @@ export function randomSaccadeInterval(): number {
       return EYE_SACCADE_INT_P[i][1] + Math.random() * EYE_SACCADE_INT_STEP
     }
   }
-  return EYE_SACCADE_INT_P[EYE_SACCADE_INT_P.length - 1][1] + Math.random() * EYE_SACCADE_INT_STEP
+  return EYE_SACCADE_INT_P.at(-1)[1] + Math.random() * EYE_SACCADE_INT_STEP
 }
diff --git a/packages/stage-ui/src/components/form/field/field-key-values.story.vue b/packages/stage-ui/src/components/form/field/field-key-values.story.vue
index b2bd109b8..e195ce95e 100644
--- a/packages/stage-ui/src/components/form/field/field-key-values.story.vue
+++ b/packages/stage-ui/src/components/form/field/field-key-values.story.vue
@@ -35,7 +35,7 @@ function removeKeyValue(index: number, headers: { key: string, value: string }[]
 }
 
 watch(emptyHeaders, (headers) => {
-  if (headers.length > 0 && (headers[headers.length - 1].key !== '' || headers[headers.length - 1].value !== '')) {
+  if (headers.length > 0 && (headers.at(-1).key !== '' || headers.at(-1).value !== '')) {
     emptyHeaders.value.push({ key: '', value: '' })
   }
 }, {
@@ -44,7 +44,7 @@ watch(emptyHeaders, (headers) => {
 })
 
 watch(singleHeader, (headers) => {
-  if (headers.length > 0 && (headers[headers.length - 1].key !== '' || headers[headers.length - 1].value !== '')) {
+  if (headers.length > 0 && (headers.at(-1).key !== '' || headers.at(-1).value !== '')) {
     singleHeader.value.push({ key: '', value: '' })
   }
 }, {
@@ -53,7 +53,7 @@ watch(singleHeader, (headers) => {
 })
 
 watch(multipleHeaders, (headers) => {
-  if (headers.length > 0 && (headers[headers.length - 1].key !== '' || headers[headers.length - 1].value !== '')) {
+  if (headers.length > 0 && (headers.at(-1).key !== '' || headers.at(-1).value !== '')) {
     multipleHeaders.value.push({ key: '', value: '' })
   }
 }, {
diff --git a/packages/stage-ui/src/components/gadgets/level-meter.vue b/packages/stage-ui/src/components/gadgets/level-meter.vue
index 503cd929a..c9369f63a 100644
--- a/packages/stage-ui/src/components/gadgets/level-meter.vue
+++ b/packages/stage-ui/src/components/gadgets/level-meter.vue
@@ -50,7 +50,7 @@ function getBarColor(_index: number, barLevel: number): string {
     }
   }
 
-  return thresholds[thresholds.length - 1]?.color || 'bg-green-500'
+  return thresholds.at(-1)?.color || 'bg-green-500'
 }
 </script>
 
diff --git a/packages/stage-ui/src/components/gadgets/time-series-chart.vue b/packages/stage-ui/src/components/gadgets/time-series-chart.vue
index 356d5875c..7e58c8b74 100644
--- a/packages/stage-ui/src/components/gadgets/time-series-chart.vue
+++ b/packages/stage-ui/src/components/gadgets/time-series-chart.vue
@@ -166,7 +166,7 @@ function downsampleSeries(values: readonly number[], maxPoints: number) {
   }
 
   // Ensure the last value remains the most recent value (avoid averaging it away)
-  result[result.length - 1] = values[values.length - 1]
+  result[result.length - 1] = values.at(-1)
   return result
 }
 
diff --git a/packages/stage-ui/src/components/widgets/poppin-text/PoppinText.web.vue b/packages/stage-ui/src/components/widgets/poppin-text/PoppinText.web.vue
index de93f5008..cc2a92c1a 100644
--- a/packages/stage-ui/src/components/widgets/poppin-text/PoppinText.web.vue
+++ b/packages/stage-ui/src/components/widgets/poppin-text/PoppinText.web.vue
@@ -28,7 +28,7 @@ watch(() => props.text, async (text) => {
   if (!text)
     return
   if (typeof text === 'string') {
-    targets.value = [...segmenter.segment(text)].map(seg => seg.segment)
+    targets.value = Array.from(segmenter.segment(text), seg => seg.segment)
   }
   else {
     abortController.value?.abort()
diff --git a/packages/stage-ui/src/composables/use-chat-session/summary.ts b/packages/stage-ui/src/composables/use-chat-session/summary.ts
index 32e2c42b9..95136e849 100644
--- a/packages/stage-ui/src/composables/use-chat-session/summary.ts
+++ b/packages/stage-ui/src/composables/use-chat-session/summary.ts
@@ -61,7 +61,7 @@ export function getSessionSummary(
     combinedReasoning: allReasoning.join('\n\n'),
     combinedSpeech: allSpeech.join('\n\n'),
     createdAt: messages[0]?.createdAt,
-    lastMessageAt: messages[messages.length - 1]?.createdAt,
+    lastMessageAt: messages.at(-1)?.createdAt,
   }
 }
 
diff --git a/packages/stage-ui/src/composables/use-scroll-to-hash.ts b/packages/stage-ui/src/composables/use-scroll-to-hash.ts
index d5f512803..921d30479 100644
--- a/packages/stage-ui/src/composables/use-scroll-to-hash.ts
+++ b/packages/stage-ui/src/composables/use-scroll-to-hash.ts
@@ -106,7 +106,7 @@ export function useScrollToHash(
 
       // Retry if element not yet found
       if (attempt < maxRetries) {
-        retryTimer = window.setTimeout(() => scrollToHash(hash, attempt + 1), retryDelay)
+        retryTimer = window.setTimeout(scrollToHash, retryDelay, hash, attempt + 1)
       }
     })
   }
diff --git a/packages/stage-ui/src/stores/character/orchestrator/store.ts b/packages/stage-ui/src/stores/character/orchestrator/store.ts
index 2f126bb84..56ebd496f 100644
--- a/packages/stage-ui/src/stores/character/orchestrator/store.ts
+++ b/packages/stage-ui/src/stores/character/orchestrator/store.ts
@@ -75,7 +75,7 @@ export const useCharacterOrchestratorStore = defineStore('character-orchestrator
   }
 
   function enqueueSparkNotify(event: WebSocketEventOf<'spark:notify'>, options?: { reason?: string, nextRunAt?: number, maxAttempts?: number }) {
-    if (!pendingNotifies.value.find(item => item.data.id === event.data.id)) {
+    if (!pendingNotifies.value.some(item => item.data.id === event.data.id)) {
       pendingNotifies.value = [...pendingNotifies.value, event]
     }
 
diff --git a/packages/stage-ui/src/stores/markdown-stress.ts b/packages/stage-ui/src/stores/markdown-stress.ts
index 3355fbf70..8ef7e882a 100644
--- a/packages/stage-ui/src/stores/markdown-stress.ts
+++ b/packages/stage-ui/src/stores/markdown-stress.ts
@@ -247,7 +247,7 @@ export const useMarkdownStressStore = defineStore('markdownStress', () => {
   function buildForFlood() {
     const line = 'for for for for for'
     // 800 lines * 5 words = 4000 tokens
-    return Array.from({ length: 800 }, () => line).join('\n')
+    return Array.from({ length: 800 }).fill(line).join('\n')
   }
 
   function generateScenario(): DevtoolsChatScenario {
diff --git a/packages/stage-ui/src/stores/providers.ts b/packages/stage-ui/src/stores/providers.ts
index 3d89c2028..4956075ec 100644
--- a/packages/stage-ui/src/stores/providers.ts
+++ b/packages/stage-ui/src/stores/providers.ts
@@ -1828,7 +1828,7 @@ export const useProvidersStore = defineStore('providers', () => {
     const defaultOptions = metadata?.defaultOptions?.() || {}
     return {
       ...defaultOptions,
-      ...(Object.prototype.hasOwnProperty.call(defaultOptions, 'baseUrl') ? {} : { baseUrl: '' }),
+      ...(Object.hasOwn(defaultOptions, 'baseUrl') ? {} : { baseUrl: '' }),
     }
   }
 
diff --git a/services/minecraft/src/cognitive/conscious/brain.test.ts b/services/minecraft/src/cognitive/conscious/brain.test.ts
index 3505677c3..6b372258b 100644
--- a/services/minecraft/src/cognitive/conscious/brain.test.ts
+++ b/services/minecraft/src/cognitive/conscious/brain.test.ts
@@ -294,7 +294,7 @@ inv;
 
     const outcome = await Promise.race([
       brain.processEvent({} as any, createPerceptionEvent()).then(() => 'done'),
-      new Promise(resolve => setTimeout(() => resolve('timeout'), 350)),
+      new Promise(resolve => setTimeout(resolve, 350, 'timeout')),
     ])
 
     expect(outcome).toBe('done')
@@ -328,7 +328,7 @@ inv;
 
     const outcome = await Promise.race([
       processing,
-      new Promise(resolve => setTimeout(() => resolve('timeout'), 500)),
+      new Promise(resolve => setTimeout(resolve, 500, 'timeout')),
     ])
 
     expect(outcome).toBe('done')
@@ -533,11 +533,11 @@ describe('brain queue coalescing', () => {
 
     const droppedResolver = vi.fn()
     brain.queue = [
-      ...Array.from({ length: 256 }, () => ({
+      ...Array.from({ length: 256 }).fill({
         event: createPerceptionEvent(),
         resolve: vi.fn(),
         reject: vi.fn(),
-      })),
+      }),
       {
         event: createNoActionFollowupEvent(),
         resolve: droppedResolver,
@@ -557,11 +557,11 @@ describe('brain queue coalescing', () => {
     const feedbackResolver = vi.fn()
 
     brain.queue = [
-      ...Array.from({ length: 256 }, () => ({
+      ...Array.from({ length: 256 }).fill({
         event: createPerceptionEvent(),
         resolve: vi.fn(),
         reject: vi.fn(),
-      })),
+      }),
       {
         event: createFeedbackEvent(),
         resolve: feedbackResolver,
@@ -612,7 +612,7 @@ describe('brain control action queue', () => {
     const brain: any = new Brain(deps)
     const outcome = await Promise.race([
       brain.processEvent({} as any, createPerceptionEvent()).then(() => 'done'),
-      new Promise(resolve => setTimeout(() => resolve('timeout'), 80)),
+      new Promise(resolve => setTimeout(resolve, 80, 'timeout')),
     ])
 
     expect(outcome).toBe('done')
diff --git a/services/minecraft/src/cognitive/conscious/context-summary.ts b/services/minecraft/src/cognitive/conscious/context-summary.ts
index 6106f681f..420999359 100644
--- a/services/minecraft/src/cognitive/conscious/context-summary.ts
+++ b/services/minecraft/src/cognitive/conscious/context-summary.ts
@@ -118,7 +118,7 @@ export function collapseOldestContexts(
     label: `(collapsed: ${labels})`,
     summary: `Collapsed ${toCollapse.length} earlier contexts (${totalTurns} turns, ${totalMessages} messages). Topics: ${labels}.`,
     startTurnId: toCollapse[0].startTurnId,
-    endTurnId: toCollapse[toCollapse.length - 1].endTurnId,
+    endTurnId: toCollapse.at(-1).endTurnId,
     messageCount: totalMessages,
     archivedAt: Date.now(),
   }
diff --git a/services/minecraft/src/cognitive/conscious/js-planner.ts b/services/minecraft/src/cognitive/conscious/js-planner.ts
index b28f11c70..e5214d70f 100644
--- a/services/minecraft/src/cognitive/conscious/js-planner.ts
+++ b/services/minecraft/src/cognitive/conscious/js-planner.ts
@@ -604,7 +604,7 @@ export class JavaScriptPlanner {
   }
 
   private defineGlobalValue(name: string, value: unknown): void {
-    if (Object.prototype.hasOwnProperty.call(this.sandbox, name))
+    if (Object.hasOwn(this.sandbox, name))
       return
 
     Object.defineProperty(this.sandbox, name, {
diff --git a/services/minecraft/src/cognitive/conscious/map-renderer.ts b/services/minecraft/src/cognitive/conscious/map-renderer.ts
index 63ce6d54f..1e979c80b 100644
--- a/services/minecraft/src/cognitive/conscious/map-renderer.ts
+++ b/services/minecraft/src/cognitive/conscious/map-renderer.ts
@@ -304,8 +304,8 @@ function renderTopDown(bot: Bot, options: Required<MapOptions>): MapResult {
 
   // Build the grid: each cell is [symbol, elevation_delta]
   const size = r * 2 + 1
-  const grid: string[][] = Array.from({ length: size }, () => Array.from({ length: size }, () => ' '))
-  const elevations: (number | null)[][] = Array.from({ length: size }, () => Array.from({ length: size }, () => null))
+  const grid: string[][] = Array.from({ length: size }).fill(Array.from({ length: size }).fill(' '))
+  const elevations: (number | null)[][] = Array.from({ length: size }).fill(Array.from({ length: size }).fill(null))
   const usedCategories = new Set<BlockCategory>()
 
   for (let dz = -r; dz <= r; dz++) {
@@ -454,7 +454,7 @@ function renderCrossSection(bot: Bot, options: Required<MapOptions>): MapResult
   const yTop = cy + r
   const yBottom = cy - r
 
-  const grid: string[][] = Array.from({ length: height }, () => Array.from({ length: width }, () => ' '))
+  const grid: string[][] = Array.from({ length: height }).fill(Array.from({ length: width }).fill(' '))
   const usedCategories = new Set<BlockCategory>()
 
   for (let dy = -r; dy <= r; dy++) {
diff --git a/services/minecraft/src/cognitive/conscious/prompts/brain-prompt.ts b/services/minecraft/src/cognitive/conscious/prompts/brain-prompt.ts
index f3ecfb797..457af2ec8 100644
--- a/services/minecraft/src/cognitive/conscious/prompts/brain-prompt.ts
+++ b/services/minecraft/src/cognitive/conscious/prompts/brain-prompt.ts
@@ -15,8 +15,7 @@ function loadTemplateFromDisk(): string {
 }
 
 function ensureTemplateLoaded(): string {
-  if (cachedTemplate == null)
-    cachedTemplate = loadTemplateFromDisk()
+  cachedTemplate ??= loadTemplateFromDisk()
   return cachedTemplate
 }
 
diff --git a/services/minecraft/src/cognitive/conscious/repl-code-normalizer.ts b/services/minecraft/src/cognitive/conscious/repl-code-normalizer.ts
index 3a64e23fb..10859d6d2 100644
--- a/services/minecraft/src/cognitive/conscious/repl-code-normalizer.ts
+++ b/services/minecraft/src/cognitive/conscious/repl-code-normalizer.ts
@@ -76,7 +76,7 @@ export function normalizeReplScript(code: string): string {
 
   const hasTopLevelReturn = sourceFile.statements.some(statement => ts.isReturnStatement(statement))
   if (!hasTopLevelReturn && sourceFile.statements.length > 0) {
-    const lastStatement = sourceFile.statements[sourceFile.statements.length - 1]
+    const lastStatement = sourceFile.statements.at(-1)
     if (ts.isExpressionStatement(lastStatement)) {
       const expressionText = getNodeText(sourceFile, lastStatement.expression)
       replacements.push({
diff --git a/services/minecraft/src/debug/tool-executor.ts b/services/minecraft/src/debug/tool-executor.ts
index f74814067..223d3a87b 100644
--- a/services/minecraft/src/debug/tool-executor.ts
+++ b/services/minecraft/src/debug/tool-executor.ts
@@ -68,7 +68,7 @@ export class ToolExecutor {
       const args: any[] = []
       const shape = (action.schema as any).shape
       for (const key in shape) {
-        if (Object.prototype.hasOwnProperty.call(validated, key)) {
+        if (Object.hasOwn(validated, key)) {
           args.push((validated as any)[key])
         }
       }
diff --git a/services/minecraft/src/debug/web/app.js b/services/minecraft/src/debug/web/app.js
index 7d5411317..dddeabfd0 100644
--- a/services/minecraft/src/debug/web/app.js
+++ b/services/minecraft/src/debug/web/app.js
@@ -642,13 +642,13 @@ class ConversationPanel {
 
   handleUpdate(data) {
     if (data.sessionBoundary) {
-      const cur = this.sessions[this.sessions.length - 1]
+      const cur = this.sessions.at(-1)
       if (cur)
         cur.greyed = true
       this.sessions.push(this._mkSession())
     }
     else {
-      const cur = this.sessions[this.sessions.length - 1]
+      const cur = this.sessions.at(-1)
       if (cur) {
         cur.messages = data.messages || []
         cur.activeContext = data.activeContext || null
diff --git a/services/minecraft/src/skills/patched-goto.ts b/services/minecraft/src/skills/patched-goto.ts
index d655c49c7..304f5e034 100644
--- a/services/minecraft/src/skills/patched-goto.ts
+++ b/services/minecraft/src/skills/patched-goto.ts
@@ -213,7 +213,7 @@ export function patchedGoto(
       settled = true
       cleanup()
       // Resolve on next tick to let pathfinder clean up
-      setTimeout(() => resolve(result), 0)
+      setTimeout(resolve, 0, result)
     }
 
     function resetTimeout() {
diff --git a/services/minecraft/src/utils/mcdata.ts b/services/minecraft/src/utils/mcdata.ts
index 46c366144..f31cf0659 100644
--- a/services/minecraft/src/utils/mcdata.ts
+++ b/services/minecraft/src/utils/mcdata.ts
@@ -194,8 +194,7 @@ export function isHostile(mob: Entity): boolean {
 }
 
 function levenshteinDistance(a: string, b: string): number {
-  const matrix: number[][] = Array.from({ length: a.length + 1 }, () =>
-    Array.from({ length: b.length + 1 }, () => 0))
+  const matrix: number[][] = Array.from({ length: a.length + 1 }).fill(Array.from({ length: b.length + 1 }).fill(0))
 
   for (let i = 0; i <= a.length; i++)
     matrix[i][0] = i
diff --git a/services/satori-bot/src/core/loop/scheduler.ts b/services/satori-bot/src/core/loop/scheduler.ts
index 8c329cd64..03e852ebe 100644
--- a/services/satori-bot/src/core/loop/scheduler.ts
+++ b/services/satori-bot/src/core/loop/scheduler.ts
@@ -62,9 +62,7 @@ export async function handleLoopStep(
       }
 
       // Manage action context size
-      if (chatCtx.actions == null) {
-        chatCtx.actions = []
-      }
+      chatCtx.actions ??= []
       chatCtx.actions = trimActions(chatCtx.actions, MAX_ACTIONS_IN_CONTEXT, ACTIONS_KEEP_ON_TRIM)
     }
 
diff --git a/services/telegram-bot/src/bots/telegram/index.ts b/services/telegram-bot/src/bots/telegram/index.ts
index 76a7f4986..b9d06a506 100644
--- a/services/telegram-bot/src/bots/telegram/index.ts
+++ b/services/telegram-bot/src/bots/telegram/index.ts
@@ -221,9 +221,7 @@ async function handleLoopStep(ctx: BotContext, chatCtx: ChatContext, incomingMes
       ctx.lastInteractedNChatIds = ctx.lastInteractedNChatIds.slice(-5)
     }
 
-    if (chatCtx.messages == null) {
-      chatCtx.messages = []
-    }
+    chatCtx.messages ??= []
     if (chatCtx.messages.length > 20) {
       const length = chatCtx.messages.length
       // pick the latest 5
@@ -231,9 +229,7 @@ async function handleLoopStep(ctx: BotContext, chatCtx: ChatContext, incomingMes
       chatCtx.messages.push(message.user(`AIRI System: Approaching to system context limit, reducing... memory..., reduced from ${length} to ${chatCtx.messages.length}, history may lost.`))
     }
 
-    if (chatCtx.actions == null) {
-      chatCtx.actions = []
-    }
+    chatCtx.actions ??= []
     if (chatCtx.actions.length > 50) {
       const length = chatCtx.actions.length
       // pick the latest 20
diff --git a/services/twitter-services/src/adapters/mcp-adapter.ts b/services/twitter-services/src/adapters/mcp-adapter.ts
index e5407f494..2fce28493 100644
--- a/services/twitter-services/src/adapters/mcp-adapter.ts
+++ b/services/twitter-services/src/adapters/mcp-adapter.ts
@@ -474,7 +474,7 @@ export class MCPAdapter {
 
         // Simple handling - send to most recent transport
         // Note: In production, should use session ID to route to correct transport
-        const transport = this.activeTransports[this.activeTransports.length - 1]
+        const transport = this.activeTransports.at(-1)
 
         // Manually handle POST message, as H3 is not Express-compatible
         const response = await transport.handleMessage(body)