diff --git a/ui/src/components/ActivityBar.tsx b/ui/src/components/ActivityBar.tsx
index 0db49cb0..c65d9b97 100644
--- a/ui/src/components/ActivityBar.tsx
+++ b/ui/src/components/ActivityBar.tsx
@@ -1,6 +1,7 @@
 import { type LucideIcon, MessageSquare, Inbox, Telescope, LineChart, GitBranch, BarChart3, Newspaper, Zap, Settings, Code2, TerminalSquare, ChevronDown, Info } from 'lucide-react'
 import { useState } from 'react'
 import { type Page } from '../App'
+import { findSectionForActivity } from '../sections'
 import { useWorkspace } from '../tabs/store'
 import type { ActivitySection, ViewSpec } from '../tabs/types'
 import { useUnreadInboxCount } from '../live/inbox-read'
@@ -233,9 +234,13 @@ export function ActivityBar({ open, onClose, onItemActivated }: ActivityBarProps
                       const sec = activitySectionFor(item.page)
                       const isActive = selectedSidebar === sec
                       const Icon = item.icon
+                      // Sidebar-less activity (no entry in SECTION_BY_KEY):
+                      // pure navigation — clicking opens the default tab
+                      // full-width; no collapse toggle, no secondary drawer.
+                      const hasSidebar = findSectionForActivity(sec) != null
                       const handleClick = () => {
                         let landedOn: ActivitySection | null
-                        if (selectedSidebar === sec) {
+                        if (selectedSidebar === sec && hasSidebar) {
                           // Same section re-clicked: toggle sidebar off. Don't
                           // touch the focused tab — collapsing the sidebar
                           // shouldn't change what's in the editor.
@@ -248,7 +253,9 @@ export function ActivityBar({ open, onClose, onItemActivated }: ActivityBarProps
                           // activities (Chat, Settings, Trading-as-Git, …) leave
                           // tab focus alone — user picks from the sidebar.
                           if (item.defaultTab) openOrFocus(item.defaultTab)
-                          landedOn = sec
+                          // Sidebar-less activities report null so mobile
+                          // dismisses instead of opening the secondary drawer.
+                          landedOn = hasSidebar ? sec : null
                         }
                         // Let parent decide the mobile transition (drill into
                         // secondary drawer vs dismiss). Default: just close.
diff --git a/ui/src/components/NewsSidebar.tsx b/ui/src/components/NewsSidebar.tsx
deleted file mode 100644
index e2ac0754..00000000
--- a/ui/src/components/NewsSidebar.tsx
+++ /dev/null
@@ -1,25 +0,0 @@
-import { useTranslation } from 'react-i18next'
-import { useWorkspace } from '../tabs/store'
-import { getFocusedTab } from '../tabs/types'
-import { SidebarRow } from './SidebarRow'
-
-/**
- * News sidebar — phase-2 placeholder. Single "All News" item that opens
- * the existing NewsPage. Phase 3+ adds source list, category filters,
- * and saved articles, each opening filtered news tabs.
- */
-export function NewsSidebar() {
-  const focusedKind = useWorkspace((state) => getFocusedTab(state)?.spec.kind ?? null)
-  const openOrFocus = useWorkspace((state) => state.openOrFocus)
-  const { t } = useTranslation()
-
-  return (
-    <div className="py-0.5">
-      <SidebarRow
-        label={t('news.allNews')}
-        active={focusedKind === 'news'}
-        onClick={() => openOrFocus({ kind: 'news', params: {} })}
-      />
-    </div>
-  )
-}
diff --git a/ui/src/i18n/locales/en.ts b/ui/src/i18n/locales/en.ts
index d04e620b..415f6a50 100644
--- a/ui/src/i18n/locales/en.ts
+++ b/ui/src/i18n/locales/en.ts
@@ -233,7 +233,6 @@ export const en = {
     webhook: 'Webhook',
   },
   news: {
-    allNews: 'All News',
     lookback1h: '1 hour',
     lookback12h: '12 hours',
     lookback24h: '24 hours',
diff --git a/ui/src/i18n/locales/ja.ts b/ui/src/i18n/locales/ja.ts
index 771aaf78..fddc9a7a 100644
--- a/ui/src/i18n/locales/ja.ts
+++ b/ui/src/i18n/locales/ja.ts
@@ -222,7 +222,6 @@ export const ja: Resources = {
     webhook: 'Webhook',
   },
   news: {
-    allNews: 'すべてのニュース',
     lookback1h: '1 時間',
     lookback12h: '12 時間',
     lookback24h: '24 時間',
diff --git a/ui/src/i18n/locales/zh-Hant.ts b/ui/src/i18n/locales/zh-Hant.ts
index 634f2c6f..d0f57d07 100644
--- a/ui/src/i18n/locales/zh-Hant.ts
+++ b/ui/src/i18n/locales/zh-Hant.ts
@@ -230,7 +230,6 @@ export const zhHant: Resources = {
     webhook: 'Webhook',
   },
   news: {
-    allNews: '所有新聞',
     lookback1h: '1 小時',
     lookback12h: '12 小時',
     lookback24h: '24 小時',
diff --git a/ui/src/i18n/locales/zh.ts b/ui/src/i18n/locales/zh.ts
index 5964df51..8948fe3e 100644
--- a/ui/src/i18n/locales/zh.ts
+++ b/ui/src/i18n/locales/zh.ts
@@ -222,7 +222,6 @@ export const zh: Resources = {
     webhook: 'Webhook',
   },
   news: {
-    allNews: '全部新闻',
     lookback1h: '1 小时',
     lookback12h: '12 小时',
     lookback24h: '24 小时',
diff --git a/ui/src/sections.tsx b/ui/src/sections.tsx
index e8b93a74..5c226af7 100644
--- a/ui/src/sections.tsx
+++ b/ui/src/sections.tsx
@@ -30,10 +30,9 @@ import { DevCategoryList } from './components/DevCategoryList'
 import { MarketSidebar } from './components/MarketSidebar'
 import { PortfolioSidebar } from './components/PortfolioSidebar'
 import { AutomationSidebar } from './components/AutomationSidebar'
-import { NewsSidebar } from './components/NewsSidebar'
 import type { ActivitySection } from './tabs/types'
 
-type NavTitleKey = 'nav.item.chat' | 'nav.item.inbox' | 'nav.item.tracked' | 'nav.item.workspaces' | 'nav.item.tradingAsGit' | 'nav.item.settings' | 'nav.item.dev' | 'nav.item.market' | 'nav.item.portfolio' | 'nav.item.automation' | 'nav.item.news'
+type NavTitleKey = 'nav.item.chat' | 'nav.item.inbox' | 'nav.item.tracked' | 'nav.item.workspaces' | 'nav.item.tradingAsGit' | 'nav.item.settings' | 'nav.item.dev' | 'nav.item.market' | 'nav.item.portfolio' | 'nav.item.automation'
 
 export interface SidebarSection {
   /** Header title shown at the top of the sidebar. */
@@ -44,7 +43,12 @@ export interface SidebarSection {
   Actions?: ComponentType
 }
 
-const SECTION_BY_KEY: Record<ActivitySection, SidebarSection> = {
+/**
+ * Activities WITHOUT an entry here are sidebar-less: clicking them in the
+ * ActivityBar opens their default tab full-width, no secondary column.
+ * (News is the first — its sidebar was a single-row placeholder.)
+ */
+const SECTION_BY_KEY: Partial<Record<ActivitySection, SidebarSection>> = {
   // Chat is the workspace-chat shortcut now — the "夺舍" of the Chat
   // shortcut by chat-template workspaces. Channel creation is no longer
   // an Action here; that affordance moved to traditional-chat.
@@ -88,10 +92,6 @@ const SECTION_BY_KEY: Record<ActivitySection, SidebarSection> = {
     titleKey: 'nav.item.automation',
     Secondary: AutomationSidebar,
   },
-  news: {
-    titleKey: 'nav.item.news',
-    Secondary: NewsSidebar,
-  },
 }
 
 /** Resolve the sidebar config for the currently selected ActivitySection. */
@@ -99,5 +99,5 @@ export function findSectionForActivity(
   section: ActivitySection | null | undefined,
 ): SidebarSection | null {
   if (!section) return null
-  return SECTION_BY_KEY[section]
+  return SECTION_BY_KEY[section] ?? null
 }