diff --git a/apps/desktop/src/app/chat/close-tab.test.ts b/apps/desktop/src/app/chat/close-tab.test.ts
index 3dba05d127..093aaba612 100644
--- a/apps/desktop/src/app/chat/close-tab.test.ts
+++ b/apps/desktop/src/app/chat/close-tab.test.ts
@@ -25,11 +25,7 @@ vi.mock('@/components/pane-shell/tree/store', () => ({
 
 vi.mock('@/store/session-states', () => ({
   closeSessionTile: (...args: unknown[]) => closeSessionTile(...args),
-  nextSessionTileForWorkspace: () => nextSessionTileForWorkspace(),
-  // preview.ts reads the focused session when stamping/deriving tabs; this
-  // suite drives the writable $selectedStoredSessionId instead, so a static
-  // null stub is enough.
-  $focusedStoredSessionId: atom<string | null>(null)
+  nextSessionTileForWorkspace: () => nextSessionTileForWorkspace()
 }))
 
 vi.mock('@/store/profile', () => ({
diff --git a/apps/desktop/src/app/chat/preview-tile.test.ts b/apps/desktop/src/app/chat/preview-tile.test.ts
index b5fe50d494..eac79de3bb 100644
--- a/apps/desktop/src/app/chat/preview-tile.test.ts
+++ b/apps/desktop/src/app/chat/preview-tile.test.ts
@@ -1,4 +1,4 @@
-import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeAll, describe, expect, it, vi } from 'vitest'
 
 vi.mock('./right-rail/preview', () => ({
   PreviewTilePane: () => null
@@ -146,90 +146,3 @@ describe('preview tiles stack, not split (#93610)', () => {
     expect(dockOf('preview-tile:file:/tmp/c.ts')?.pos).toBe('right')
   })
 })
-
-// ---------------------------------------------------------------------------
-// Session-scoped rail (#73890): only the FOCUSED session's tabs (plus pins)
-// become panes, so switching sessions swaps the drawer, and pinning a tab
-// surfaces it in every session.
-// ---------------------------------------------------------------------------
-
-describe('preview tiles mirror the visible session tabs', () => {
-  beforeEach(() => {
-    window.localStorage.clear()
-    vi.resetModules()
-  })
-
-  afterEach(() => {
-    vi.resetModules()
-  })
-
-  async function setup() {
-    const preview = await import('@/store/preview')
-    const session = await import('@/store/session')
-    const tree = await import('@/components/pane-shell/tree/store')
-    const model = await import('@/components/pane-shell/tree/model')
-    const { registry } = await import('@/contrib/registry')
-    const { watchPreviewTiles } = await import('./preview-tile')
-
-    registry.register({
-      area: 'panes',
-      data: { placement: 'main', uncloseable: true },
-      id: 'workspace',
-      render: () => null,
-      title: 'workspace'
-    })
-    tree.declareDefaultTree(model.group(['workspace'], { active: 'workspace', id: 'grp-main' }))
-    // The app root wires registry changes into the tree; mirror it here.
-    tree.watchContributedPanes()
-    watchPreviewTiles()
-
-    return { model, preview, session, tree }
-  }
-
-  const htmlTarget = (path: string) =>
-    ({
-      kind: 'file',
-      label: path.split('/').at(-1) ?? path,
-      path,
-      previewKind: 'html',
-      source: path,
-      url: `file://${path}`
-    }) as const
-
-  it('renders only the focused session previews, pinning spans sessions', async () => {
-    const { preview, session, tree } = await setup()
-
-    session.$selectedStoredSessionId.set('sess-1')
-    preview.openPreview(htmlTarget('/work/a.html'))
-
-    expect(tree.treePanesWithPrefix('preview-tile:')).toHaveLength(1)
-
-    // Switching sessions hides the pane (the tab stays open in the store).
-    session.$selectedStoredSessionId.set('sess-2')
-    expect(tree.treePanesWithPrefix('preview-tile:')).toHaveLength(0)
-    expect(preview.$previewTabs.get()).toHaveLength(1)
-
-    // Pinning makes it visible again in the new session.
-    preview.setPreviewTabPinned(preview.$previewTabs.get()[0]!.id, true)
-    expect(tree.treePanesWithPrefix('preview-tile:')).toHaveLength(1)
-
-    // And closing the tab removes the pane for good.
-    preview.closeRightRailTab(preview.$previewTabs.get()[0]!.id)
-    expect(tree.treePanesWithPrefix('preview-tile:')).toHaveLength(0)
-  })
-
-  it('does not create panes for another session tabs', async () => {
-    const { preview, session, tree } = await setup()
-
-    session.$selectedStoredSessionId.set('sess-1')
-    preview.openPreview(htmlTarget('/work/a.html'))
-
-    session.$selectedStoredSessionId.set('sess-2')
-    preview.openPreview(htmlTarget('/work/b.html'))
-
-    expect(tree.treePanesWithPrefix('preview-tile:')).toHaveLength(1)
-
-    session.$selectedStoredSessionId.set('sess-1')
-    expect(tree.treePanesWithPrefix('preview-tile:')).toHaveLength(1)
-  })
-})
diff --git a/apps/desktop/src/app/chat/preview-tile.tsx b/apps/desktop/src/app/chat/preview-tile.tsx
index b9776adb05..534ac881f1 100644
--- a/apps/desktop/src/app/chat/preview-tile.tsx
+++ b/apps/desktop/src/app/chat/preview-tile.tsx
@@ -28,9 +28,8 @@ import { openExternalLink } from '@/lib/external-link'
 import { $rightRailActiveTabId, type RightRailTabId, selectRightRailTab } from '@/store/layout'
 import {
   $browserPages,
-  $dockedVisiblePreviewTabs,
+  $dockedPreviewTabs,
   $previewTabs,
-  $visiblePreviewTabs,
   adoptPersistedBrowserTab,
   type BrowserPage,
   closeRightRailTab,
@@ -38,8 +37,7 @@ import {
   markBrowserTabPopped,
   newBrowserTab,
   popOutBrowserTab,
-  type PreviewTarget,
-  setPreviewTabPinned
+  type PreviewTarget
 } from '@/store/preview'
 import { explicitOpenBlocksZone, PREVIEW_TILE_PREFIX } from '@/store/preview-explicit'
 import { canOpenBrowserWindow } from '@/store/windows'
@@ -98,26 +96,6 @@ function browserTabMenuPrefix(tabId: string) {
   )
 }
 
-/** Pin/unpin for EVERY preview tab's zone menu: pinned tabs are the explicit
- *  cross-session workspace, everything else belongs to the session that
- *  opened it (#73890). URL tabs keep their browser rows below it. */
-function previewTabMenuPrefix(tabId: string) {
-  const pinned = Boolean($previewTabs.get().find(tab => tab.id === tabId)?.pinned)
-  const browserRows = browserTabMenuPrefix(tabId)
-
-  return (kit: MenuKit) => (
-    <>
-      {renderActionItem(kit, {
-        icon: pinned ? 'pinned' : 'pin',
-        key: 'pin',
-        label: translateNow(pinned ? 'preview.unpin' : 'preview.pin'),
-        onSelect: () => setPreviewTabPinned(tabId, !pinned)
-      })}
-      {browserRows?.(kit) ?? null}
-    </>
-  )
-}
-
 /** Tab title. A URL tab is titled by the CONTRIBUTION as the surface — see
  *  `BrowserTabLabel` for the live page name the strip actually renders — so
  *  navigating doesn't re-register the pane on every hop. A file names the
@@ -212,7 +190,7 @@ function existingPreviewAnchor(tabId: string): string | undefined {
     return inTree
   }
 
-  const other = $dockedVisiblePreviewTabs.get().find(tab => tab.id !== tabId)
+  const other = $dockedPreviewTabs.get().find(tab => tab.id !== tabId)
 
   return other ? previewPaneId(other.id) : undefined
 }
@@ -242,23 +220,7 @@ export function watchPreviewTiles(): void {
   }
 
   $rightRailActiveTabId.listen(reveal)
-  // Visible-list changes: a re-open of the already-active tab refreshes the
-  // target through the visible list too, while tab mutations belonging to a
-  // BACKGROUND session must not try to reveal panes that are not mounted.
-  $visiblePreviewTabs.listen(reveal)
-
-  // A session switch (or an unpin) can leave the active tab outside the
-  // visible set — re-home the selection to the first visible tab so the strip
-  // and the pane never point at a hidden preview.
-  const rehome = () => {
-    const visible = $visiblePreviewTabs.get()
-
-    if (!visible.some(tab => tab.id === $rightRailActiveTabId.get())) {
-      selectRightRailTab(visible[0]?.id ?? null)
-    }
-  }
-
-  $visiblePreviewTabs.listen(rehome)
+  $previewTabs.listen(reveal)
 
   // And the reverse: clicking a preview TAB activates its pane in the TREE
   // only, so the store's selection must follow or `$previewTarget` (⌘L quote
@@ -299,12 +261,11 @@ export function watchPreviewTiles(): void {
 }
 
 const watchPreviewTileMirror = paneMirror<{ id: string }>({
-  // Only the FOCUSED session's tabs (plus pins) become panes — switching
-  // sessions swaps the drawer; a hidden tab's pane leaves the tree without
-  // closing the tab (paneMirror's sync disposes, it doesn't call close).
-  // Composed with $dockedPreviewTabs so a popped-out Browser pane also
-  // leaves the docked tree.
-  source: $dockedVisiblePreviewTabs,
+  source: $dockedPreviewTabs,
+  // Unscoped on purpose. `$previewTabs` is one global Browser/file surface —
+  // clicking a link in a bot chat must open the same pane Sessions already
+  // shows. Scoping this to `sessions` filtered the pane out of Bot Mode, so
+  // `openPreview` ran and the click looked like a no-op.
   key: tab => tab.id,
   prefix: PREVIEW_TILE_PREFIX,
   // The FIRST preview still opens its own zone docked beside main (identical
@@ -321,10 +282,7 @@ const watchPreviewTileMirror = paneMirror<{ id: string }>({
   // A Browser is a vessel, so there can be more of it — a file peek is one of
   // a kind and leaves the strip's "+" to whatever else the zone holds.
   newTab: tabId => (targetFor(tabId)?.kind === 'url' ? newBrowserTab : undefined),
-  // Pin/unpin rides the zone tab menu for every preview tab: pinned tabs are
-  // the explicit cross-session workspace, everything else belongs to the
-  // session that opened it (#73890).
-  tabMenuPrefix: previewTabMenuPrefix,
+  tabMenuPrefix: browserTabMenuPrefix,
   lifecycleKeepAlive: tabId => {
     const target = targetFor(tabId)
 
diff --git a/apps/desktop/src/app/session/hooks/use-session-actions/index.ts b/apps/desktop/src/app/session/hooks/use-session-actions/index.ts
index 2ec6f6a6f6..8faabcd810 100644
--- a/apps/desktop/src/app/session/hooks/use-session-actions/index.ts
+++ b/apps/desktop/src/app/session/hooks/use-session-actions/index.ts
@@ -47,7 +47,6 @@ import {
 import { $gatewaySwitching } from '@/store/gateway-switch'
 import { $pinnedSessionIds } from '@/store/layout'
 import { clearNotifications, notify, notifyError } from '@/store/notifications'
-import { prunePreviewTabsForSession } from '@/store/preview'
 import {
   $activeGatewayProfile,
   $gatewaySwapTarget,
@@ -3298,14 +3297,6 @@ export function useSessionActions({
         // the closing runtime id — the journal keys on the stored id.
         purgeInFlightTurnJournals([...removedIds, closingRuntimeId])
 
-        // Preview tabs are session-owned: drop them with the session (pinned
-        // tabs survive — they belong to the workspace, not the session).
-        for (const id of removedIds) {
-          if (id) {
-            prunePreviewTabsForSession(id)
-          }
-        }
-
         if (closingRuntimeId) {
           clearQueuedPrompts(closingRuntimeId)
           clearSessionControl(closingRuntimeId)
diff --git a/apps/desktop/src/i18n/ar_artifacts.ts b/apps/desktop/src/i18n/ar_artifacts.ts
index 9876dc7c0e..5e38757d0c 100644
--- a/apps/desktop/src/i18n/ar_artifacts.ts
+++ b/apps/desktop/src/i18n/ar_artifacts.ts
@@ -55,8 +55,6 @@ export const arArtifacts = {
   },
   preview: {
     tab: 'معاينة',
-    pin: 'تثبيت في مساحة العمل',
-    unpin: 'إلغاء التثبيت من مساحة العمل',
     closePane: 'إغلاق جزء المعاينة',
     loading: 'جار تحميل المعاينة',
     unavailable: 'المعاينة غير متاحة',
diff --git a/apps/desktop/src/i18n/en.ts b/apps/desktop/src/i18n/en.ts
index 5931026a62..3d1e944454 100644
--- a/apps/desktop/src/i18n/en.ts
+++ b/apps/desktop/src/i18n/en.ts
@@ -4862,8 +4862,6 @@ export const en: Translations = {
 
   preview: {
     tab: 'Preview',
-    pin: 'Pin to workspace',
-    unpin: 'Unpin from workspace',
     closePane: 'Close preview pane',
     loading: 'Loading preview',
     unavailable: 'Preview unavailable',
diff --git a/apps/desktop/src/i18n/ja.ts b/apps/desktop/src/i18n/ja.ts
index 3b0687ccbf..b79c56c868 100644
--- a/apps/desktop/src/i18n/ja.ts
+++ b/apps/desktop/src/i18n/ja.ts
@@ -3585,8 +3585,6 @@ export const ja = defineLocale({
 
   preview: {
     tab: 'プレビュー',
-    pin: 'ワークスペースにピン留め',
-    unpin: 'ワークスペースからピン留めを外す',
     closePane: 'プレビューペインを閉じる',
     loading: 'プレビューを読み込み中',
     unavailable: 'プレビューは利用できません',
diff --git a/apps/desktop/src/i18n/types.ts b/apps/desktop/src/i18n/types.ts
index 76d1efcede..2629c6484c 100644
--- a/apps/desktop/src/i18n/types.ts
+++ b/apps/desktop/src/i18n/types.ts
@@ -4110,8 +4110,6 @@ export interface Translations {
 
   preview: {
     tab: string
-    pin: string
-    unpin: string
     closePane: string
     loading: string
     unavailable: string
diff --git a/apps/desktop/src/i18n/zh-hant_artifacts.ts b/apps/desktop/src/i18n/zh-hant_artifacts.ts
index a8928fd880..589fe485d9 100644
--- a/apps/desktop/src/i18n/zh-hant_artifacts.ts
+++ b/apps/desktop/src/i18n/zh-hant_artifacts.ts
@@ -58,8 +58,6 @@ export const zhHantArtifacts = {
 
   preview: {
     tab: '預覽',
-    pin: '固定到工作區',
-    unpin: '從工作區取消固定',
     closePane: '關閉預覽窗格',
     loading: '正在載入預覽',
     unavailable: '預覽不可用',
diff --git a/apps/desktop/src/i18n/zh.ts b/apps/desktop/src/i18n/zh.ts
index 355fa64af2..2bb89c04c2 100644
--- a/apps/desktop/src/i18n/zh.ts
+++ b/apps/desktop/src/i18n/zh.ts
@@ -4557,8 +4557,6 @@ export const zh = defineLocale({
 
   preview: {
     tab: '预览',
-    pin: '固定到工作区',
-    unpin: '从工作区取消固定',
     closePane: '关闭预览面板',
     loading: '正在加载预览',
     unavailable: '预览不可用',
diff --git a/apps/desktop/src/store/preview.test.ts b/apps/desktop/src/store/preview.test.ts
index 09605586f1..6cfa1a9988 100644
--- a/apps/desktop/src/store/preview.test.ts
+++ b/apps/desktop/src/store/preview.test.ts
@@ -7,7 +7,6 @@ import {
   $previewServerRestartStatus,
   $previewTabs,
   $previewTarget,
-  $visiblePreviewTabs,
   beginPreviewServerRestart,
   closeBrowserPreviewMatchingLiveUrl,
   closePreviewForSource,
@@ -23,12 +22,9 @@ import {
   previewTabId,
   type PreviewTarget,
   progressPreviewServerRestart,
-  prunePreviewTabsForSession,
   renderedHtmlTarget,
-  setPreviewRenderMode,
-  setPreviewTabPinned
+  setPreviewRenderMode
 } from './preview'
-import { $selectedStoredSessionId } from './session'
 
 function fileTarget(source: string): PreviewTarget {
   return { kind: 'file', label: source, path: source, previewKind: 'html', source, url: `file://${source}` }
@@ -46,7 +42,6 @@ describe('preview store', () => {
   beforeEach(() => {
     $browserPages.set({})
     $previewServerRestart.set(null)
-    $selectedStoredSessionId.set(null)
     closeRightRail()
     window.localStorage.clear()
   })
@@ -54,7 +49,6 @@ describe('preview store', () => {
   afterEach(() => {
     $browserPages.set({})
     $previewServerRestart.set(null)
-    $selectedStoredSessionId.set(null)
     closeRightRail()
     window.localStorage.clear()
   })
@@ -74,7 +68,7 @@ describe('preview store', () => {
   it('opens the pane and fronts the new tab', () => {
     openPreview(fileTarget('/work/demo.html'))
 
-    expect($rightRailActiveTabId.get()).toBe('file:/work/demo.html')
+    expect($rightRailActiveTabId.get()).toBe('file:file:///work/demo.html')
     expect($previewTarget.get()?.path).toBe('/work/demo.html')
   })
 
@@ -393,208 +387,3 @@ describe('preview store', () => {
     expect(restored.map(tab => tab.target.path)).toEqual(['/work/alive.html'])
   })
 })
-
-describe('preview session scoping', () => {
-  afterEach(() => {
-    $selectedStoredSessionId.set(null)
-    closeRightRail()
-    window.localStorage.clear()
-  })
-
-  it('stamps the active session on tabs it opens', () => {
-    $selectedStoredSessionId.set('sess-1')
-    openPreview(fileTarget('/work/demo.html'))
-
-    expect($previewTabs.get()[0]?.sessionId).toBe('sess-1')
-  })
-
-  it('shows only the active session tabs plus pinned ones', () => {
-    $selectedStoredSessionId.set('sess-1')
-    openPreview(fileTarget('/work/a.html'))
-    $selectedStoredSessionId.set('sess-2')
-    openPreview(fileTarget('/work/b.html'))
-
-    expect($visiblePreviewTabs.get().map(tab => tab.target.path)).toEqual(['/work/b.html'])
-
-    // Pinning makes the first session's tab visible in every session.
-    const aTab = $previewTabs.get().find(tab => tab.target.path === '/work/a.html')
-    setPreviewTabPinned(aTab!.id, true)
-
-    expect(
-      $visiblePreviewTabs
-        .get()
-        .map(tab => tab.target.path)
-        .sort()
-    ).toEqual(['/work/a.html', '/work/b.html'])
-
-    // Unpinning hides it from the other session again.
-    setPreviewTabPinned(aTab!.id, false)
-    expect($visiblePreviewTabs.get().map(tab => tab.target.path)).toEqual(['/work/b.html'])
-  })
-
-  it('prunes a deleted session tabs but keeps its pins', () => {
-    $selectedStoredSessionId.set('sess-1')
-    openPreview(fileTarget('/work/a.html'))
-    setPreviewTabPinned($previewTabs.get()[0]!.id, true)
-    $selectedStoredSessionId.set('sess-2')
-    openPreview(fileTarget('/work/b.html'))
-
-    prunePreviewTabsForSession('sess-2')
-    expect($previewTabs.get().map(tab => tab.target.path)).toEqual(['/work/a.html'])
-
-    // Pinned tabs belong to the workspace, not the session that opened them.
-    prunePreviewTabsForSession('sess-1')
-    expect($previewTabs.get().map(tab => tab.target.path)).toEqual(['/work/a.html'])
-  })
-
-  it('adopts ownerless draft tabs when a session appears', () => {
-    openPreview(fileTarget('/work/draft.html'))
-    expect($previewTabs.get()[0]?.sessionId).toBeUndefined()
-
-    $selectedStoredSessionId.set('sess-new')
-    expect($previewTabs.get()[0]?.sessionId).toBe('sess-new')
-    // The id is rekeyed onto the session-scoped form so a later open of the
-    // same file dedupes instead of stacking.
-    expect($previewTabs.get()[0]?.id).toBe('file:sess-new:/work/draft.html')
-    expect($visiblePreviewTabs.get().map(tab => tab.target.path)).toEqual(['/work/draft.html'])
-  })
-
-  it('canonicalizes file identities across entry points', () => {
-    expect(previewTabId(fileTarget('/work/demo.html'))).toBe('file:/work/demo.html')
-
-    const viaPlainPath = previewTabId({ ...fileTarget('/work/demo.html'), url: '/work/demo.html' })
-    expect(viaPlainPath).toBe('file:/work/demo.html')
-  })
-
-  it('scopes file tab ids to the session, so two sessions can open the same file', () => {
-    expect(previewTabId(fileTarget('/work/demo.html'), 'sess-1')).toBe('file:sess-1:/work/demo.html')
-    expect(previewTabId(fileTarget('/work/demo.html'), 'sess-2')).toBe('file:sess-2:/work/demo.html')
-
-    $selectedStoredSessionId.set('sess-1')
-    openPreview(fileTarget('/work/demo.html'))
-    $selectedStoredSessionId.set('sess-2')
-    openPreview(fileTarget('/work/demo.html'))
-
-    const tabs = $previewTabs.get()
-
-    expect(tabs).toHaveLength(2)
-    expect(tabs[0]).toMatchObject({ sessionId: 'sess-1', id: 'file:sess-1:/work/demo.html' })
-    expect(tabs[1]).toMatchObject({ sessionId: 'sess-2', id: 'file:sess-2:/work/demo.html' })
-    expect($visiblePreviewTabs.get()).toHaveLength(1)
-  })
-
-  it('re-opening the same file in the same session keeps the tab owner and pin', () => {
-    $selectedStoredSessionId.set('sess-1')
-    openPreview(fileTarget('/work/demo.html'))
-    setPreviewTabPinned($previewTabs.get()[0]!.id, true)
-
-    openPreview({ ...fileTarget('/work/demo.html'), label: 'refreshed' })
-
-    expect($previewTabs.get()).toHaveLength(1)
-    expect($previewTabs.get()[0]).toMatchObject({ sessionId: 'sess-1', pinned: true })
-    expect($previewTabs.get()[0]?.target.label).toBe('refreshed')
-  })
-
-  it('unpinning an ownerless tab adopts the current session', () => {
-    openPreview(fileTarget('/work/legacy.html'))
-    setPreviewTabPinned($previewTabs.get()[0]!.id, true)
-
-    $selectedStoredSessionId.set('sess-1')
-    setPreviewTabPinned($previewTabs.get()[0]!.id, false)
-
-    expect($previewTabs.get()[0]).toMatchObject({ pinned: false, sessionId: 'sess-1' })
-    expect($previewTabs.get()[0]?.id).toBe('file:sess-1:/work/legacy.html')
-  })
-
-  it('closes by source only within the current session', () => {
-    $selectedStoredSessionId.set('sess-1')
-    openPreview(fileTarget('/work/a.html'))
-    $selectedStoredSessionId.set('sess-2')
-    openPreview(fileTarget('/work/a.html'))
-
-    // The hidden session's tab must not be closed by the other session's row.
-    expect(closePreviewForSource('/work/a.html')).toBe(true)
-    expect($previewTabs.get()).toHaveLength(1)
-    expect($previewTabs.get()[0]?.sessionId).toBe('sess-1')
-  })
-
-  it('reopens a pinned legacy row instead of stacking a second tab', () => {
-    // A migrated legacy row: pinned, unprefixed id, no owner.
-    $previewTabs.set([{ id: 'file:/work/a.html', target: fileTarget('/work/a.html'), pinned: true }])
-
-    $selectedStoredSessionId.set('sess-1')
-    openPreview(fileTarget('/work/a.html'))
-
-    expect($previewTabs.get()).toHaveLength(1)
-    expect($previewTabs.get()[0]).toMatchObject({ pinned: true, sessionId: 'sess-1' })
-    expect($previewTabs.get()[0]?.id).toBe('file:sess-1:/work/a.html')
-    expect($visiblePreviewTabs.get()).toHaveLength(1)
-  })
-
-  it('adoption dedupes against an already session-scoped row', () => {
-    // Both rows for the same file coexist before the session appears.
-    $previewTabs.set([
-      { id: 'file:/work/a.html', target: fileTarget('/work/a.html') },
-      { id: 'file:sess-1:/work/a.html', target: fileTarget('/work/a.html'), sessionId: 'sess-1' }
-    ])
-
-    $selectedStoredSessionId.set('sess-1')
-
-    expect($previewTabs.get()).toHaveLength(1)
-    expect($previewTabs.get()[0]?.id).toBe('file:sess-1:/work/a.html')
-  })
-
-  it('adoption dedupe keeps the active selection valid', () => {
-    // The colliding row is the ACTIVE tab when adoption rekeys the draft
-    // onto the same id — the survivor carries that id, so the selection must
-    // not dangle.
-    $previewTabs.set([
-      { id: 'file:/work/a.html', target: fileTarget('/work/a.html') },
-      { id: 'file:sess-1:/work/a.html', target: fileTarget('/work/a.html'), sessionId: 'sess-1' }
-    ])
-    selectRightRailTab('file:sess-1:/work/a.html')
-
-    $selectedStoredSessionId.set('sess-1')
-
-    expect($previewTabs.get()).toHaveLength(1)
-    expect($rightRailActiveTabId.get()).toBe('file:sess-1:/work/a.html')
-  })
-
-  it('migrates legacy unscoped tabs to pinned and rekeys their ids', () => {
-    const raw = JSON.stringify([
-      { id: 'file:file:///work/a.html', target: fileTarget('/work/a.html') },
-      { id: 'file:file:///work/b.html', target: fileTarget('/work/b.html'), sessionId: 'sess-9' }
-    ])
-
-    const decoded = decodePreviewTabs(raw)
-
-    expect(decoded).toHaveLength(2)
-    expect(decoded[0]).toMatchObject({ id: 'file:/work/a.html', pinned: true })
-    expect(decoded[1]?.id).toBe('file:sess-9:/work/b.html')
-    expect(decoded[1]?.sessionId).toBe('sess-9')
-    expect(decoded[1]?.pinned).toBeUndefined()
-  })
-
-  it('does not re-pin a persisted unpinned row', () => {
-    const raw = JSON.stringify([
-      { id: 'file:/work/a.html', target: fileTarget('/work/a.html'), sessionId: 'sess-1', pinned: false }
-    ])
-
-    const decoded = decodePreviewTabs(raw)
-
-    expect(decoded[0]?.pinned).toBe(false)
-  })
-
-  it('dedupes the same file persisted under both old and canonical ids', () => {
-    const raw = JSON.stringify([
-      { id: 'file:file:///work/a.html', target: fileTarget('/work/a.html') },
-      { id: 'file:/work/a.html', target: { ...fileTarget('/work/a.html'), label: 'updated' } }
-    ])
-
-    const decoded = decodePreviewTabs(raw)
-
-    expect(decoded).toHaveLength(1)
-    expect(decoded[0]?.id).toBe('file:/work/a.html')
-    expect(decoded[0]?.target.label).toBe('updated')
-  })
-})
diff --git a/apps/desktop/src/store/preview.ts b/apps/desktop/src/store/preview.ts
index 8c83db786f..2c7af63608 100644
--- a/apps/desktop/src/store/preview.ts
+++ b/apps/desktop/src/store/preview.ts
@@ -13,7 +13,6 @@ import { recordFeatureUse } from './desktop-metrics'
 import { $rightRailActiveTabId, type RightRailTabId, selectRightRailTab } from './layout'
 import { clearExplicitPreviewOpen, noteExplicitPreviewOpen, PREVIEW_TILE_PREFIX } from './preview-explicit'
 import { normalizeProfileKey } from './profile'
-import { $focusedStoredSessionId } from './session-focus'
 import { canOpenBrowserWindow, openBrowserInNewWindow } from './windows'
 
 /**
@@ -74,12 +73,6 @@ export interface PreviewServerRestart {
 export interface PreviewTab {
   id: RightRailTabId
   target: PreviewTarget
-  /** The session that opened the tab. Absent only on legacy rows written
-   *  before session scoping (decodePreviewTabs migrates those to pinned). */
-  sessionId?: string
-  /** Pinned tabs render in EVERY session — the explicit cross-session
-   *  workspace. Everything else is visible only in the session that opened it. */
-  pinned?: boolean
 }
 
 const TABS_STORAGE_KEY = 'hermes.desktop.previewTabs.v2'
@@ -142,44 +135,17 @@ export function decodePreviewTabs(raw: string): PreviewTab[] {
 }
 
 function parseTabList(parsed: unknown): PreviewTab[] {
-  const pdfUpgraded = (Array.isArray(parsed) ? parsed.filter(isPreviewTab) : [])
-    .map(tab =>
-      isPdfFileTarget(tab.target) && tab.target.previewKind === 'binary'
-        ? { ...tab, target: { ...tab.target, previewKind: 'pdf' as const } }
-        : tab
-    )
-    // Drop tombstoned file tabs (a previous session confirmed the file is
-    // gone). Keeping them would re-probe a known-dead path on every boot.
-    .filter(tab => !tab.target.missing)
-
-  // Legacy rows (written before session scoping) have no owner and no way to
-  // recover one — keep them as workspace-pinned rather than dropping them or
-  // dumping every stale tab into one chat. Explicit `!== undefined` checks:
-  // a persisted `pinned: false` must not be re-pinned.
-  const owned = pdfUpgraded.map(tab =>
-    tab.sessionId !== undefined || tab.pinned !== undefined ? tab : { ...tab, pinned: true }
+  return (
+    (Array.isArray(parsed) ? parsed.filter(isPreviewTab) : [])
+      .map(tab =>
+        isPdfFileTarget(tab.target) && tab.target.previewKind === 'binary'
+          ? { ...tab, target: { ...tab.target, previewKind: 'pdf' as const } }
+          : tab
+      )
+      // Drop tombstoned file tabs (a previous session confirmed the file is
+      // gone). Keeping them would re-probe a known-dead path on every boot.
+      .filter(tab => !tab.target.missing)
   )
-
-  // One Browser: rekey restored URL tabs onto the singleton id (rows written
-  // before the id existed carried one id per address). File tabs rekey onto
-  // their session-scoped canonical id. Keep only the LAST row per id — the
-  // most recently opened wins.
-  const lastUrl = owned.findLast(tab => tab.target.kind === 'url')
-  const deduped = new Map<string, PreviewTab>()
-
-  for (const tab of owned) {
-    if (tab.target.kind === 'url' && tab !== lastUrl) {
-      continue
-    }
-
-    const id =
-      tab.target.kind === 'url' || tab.target.kind === 'file'
-        ? previewTabId(tab.target, tab.sessionId)
-        : tab.id
-    deduped.set(id, { ...tab, id })
-  }
-
-  return [...deduped.values()]
 }
 
 /** The tabs a profile's rail is showing, keyed by profile. */
@@ -374,63 +340,6 @@ if (typeof window !== 'undefined') {
   }
 }
 
-/** Tabs the ACTIVE session sees: its own tabs plus everything pinned. The
- *  layout-tree mirror renders only these, so a session switch swaps the drawer
- *  and pinned tabs are the explicit cross-session workspace. While no session
- *  exists (a fresh draft), ownerless tabs stay visible. */
-export const $visiblePreviewTabs = computed(
-  [$previewTabs, $focusedStoredSessionId],
-  (tabs, sessionId) =>
-    tabs.filter(
-      tab => tab.pinned || tab.sessionId === sessionId || (sessionId == null && tab.sessionId == null)
-    )
-)
-
-// A fresh draft has no session yet, so tabs opened there are ownerless — adopt
-// them into the session the moment one exists (rekeying file ids onto the
-// session-scoped form, so a later open of the same file dedupes), or the
-// drawer would silently lose them at first send.
-$focusedStoredSessionId.listen(sessionId => {
-  if (sessionId == null) {
-    return
-  }
-
-  const tabs = $previewTabs.get()
-
-  if (tabs.some(tab => tab.sessionId == null && !tab.pinned)) {
-    const activeId = $rightRailActiveTabId.get()
-    let newActiveId = activeId
-    const updated = tabs.map(tab => {
-      if (tab.sessionId != null || tab.pinned) {
-        return tab
-      }
-
-      const nextId = tab.target.kind === 'file' ? previewTabId(tab.target, sessionId) : tab.id
-
-      if (tab.id === activeId) {
-        newActiveId = nextId
-      }
-
-      return { ...tab, id: nextId, sessionId }
-    })
-
-    // A rekey can collide with an already session-scoped row of the same file
-    // (defensive: adoption runs synchronously with the focus change, so a real
-    // open can't interleave — but keep the no-duplicate invariant explicit).
-    const deduped = new Map<string, PreviewTab>()
-
-    for (const tab of updated) {
-      deduped.set(tab.id, tab)
-    }
-
-    $previewTabs.set([...deduped.values()])
-
-    if (newActiveId !== activeId) {
-      selectRightRailTab(newActiveId)
-    }
-  }
-})
-
 /** The tab the rail actually shows. A stale or missing selection falls back to
  *  the first tab, so the strip, `⌘W`, and the pane never disagree about which
  *  tab is on screen. */
@@ -439,7 +348,7 @@ function resolveActiveTab(tabs: PreviewTab[], activeTabId: RightRailTabId | null
 }
 
 function activePreviewTab(): PreviewTab | null {
-  return resolveActiveTab($visiblePreviewTabs.get(), $rightRailActiveTabId.get())
+  return resolveActiveTab($previewTabs.get(), $rightRailActiveTabId.get())
 }
 
 // A restored active id whose tab didn't survive validation would leave the rail
@@ -448,13 +357,13 @@ selectRightRailTab(activePreviewTab()?.id ?? null)
 
 /** The target the rail is currently showing, or null when it has no tabs. */
 export const $previewTarget = computed(
-  [$visiblePreviewTabs, $rightRailActiveTabId],
+  [$previewTabs, $rightRailActiveTabId],
   (tabs, activeTabId) => resolveActiveTab(tabs, activeTabId)?.target ?? null
 )
 
-/** Raw `source` strings of every tab the active session sees, for the composer
- *  rows that toggle a preview open and closed by the target they were handed. */
-export const $previewTabSources = computed($visiblePreviewTabs, tabs => tabs.map(tab => tab.target.source))
+/** Raw `source` strings of every open tab, for the composer rows that toggle a
+ *  preview open and closed by the target they were handed. */
+export const $previewTabSources = computed($previewTabs, tabs => tabs.map(tab => tab.target.source))
 
 export interface BrowserPage {
   title: string
@@ -643,13 +552,6 @@ export const $dockedPreviewTabs = computed([$previewTabs, $poppedBrowserTabIds],
   popped.size === 0 ? tabs : tabs.filter(tab => !popped.has(tab.id))
 )
 
-/** The FOCUSED session's tabs that still belong in the docked layout tree —
- *  the layout-tree mirror renders only these (#73890): switching sessions
- *  swaps the drawer, and a popped-out Browser pane stays out. */
-export const $dockedVisiblePreviewTabs = computed([$visiblePreviewTabs, $poppedBrowserTabIds], (tabs, popped) =>
-  popped.size === 0 ? tabs : tabs.filter(tab => !popped.has(tab.id))
-)
-
 export const $previewReloadRequest = atom(0)
 export const $previewServerRestart = atom<PreviewServerRestart | null>(null)
 export const $previewServerRestartStatus = computed($previewServerRestart, restart => restart?.status ?? 'idle')
@@ -657,22 +559,8 @@ export const $previewServerRestartStatus = computed($previewServerRestart, resta
 /** The tab that owns `target`. Files and artifacts are keyed by IDENTITY —
  *  the same file is always the same tab, reopening it re-fronts the one it
  *  already has. A URL has no identity here: a Browser tab is a vessel you
- *  navigate, so it is picked (`browserTabId`) rather than derived.
- *
- *  A FILE tab's identity additionally carries the session that opened it —
- *  the same file opened in two conversations is two tabs, each owned by its
- *  session (the session-scoped rail, #73890). Legacy rows (no session) keep
- *  the unprefixed key. The `file://` scheme is stripped so the two entry
- *  points (a `file://` URL vs a plain path) resolve to the same key. */
-function canonicalFileKey(target: PreviewTarget): string {
-  return (target.path || target.url).replace(/^file:\/\//, '')
-}
-
-export function previewTabId(target: PreviewTarget, sessionId?: null | string): RightRailTabId {
-  if (target.kind === 'file') {
-    return `file:${sessionId ? `${sessionId}:` : ''}${canonicalFileKey(target)}`
-  }
-
+ *  navigate, so it is picked (`browserTabId`) rather than derived. */
+export function previewTabId(target: PreviewTarget): RightRailTabId {
   return `${target.kind}:${target.url}`
 }
 
@@ -736,36 +624,14 @@ export function setPreviewRenderMode(tabId: string, renderMode: PreviewRenderMod
 
 /** Open (or re-front) the tab for `target`. Re-opening an existing tab refreshes
  *  its target so a stale label/path can't outlive the thing it points at. The
- *  only way anything reaches a preview.
- *
- *  The tab belongs to the session that was active when it opened (a re-open
- *  of an existing tab keeps the tab's owner and pin state — only the target
- *  refreshes). A PINNED row for the same file carries the unprefixed
- *  (legacy) id, so a session-scoped open would otherwise stack a second tab
- *  for the same file: reuse the pinned row instead — refreshed, still
- *  pinned, fronted. Never steal another session's owned tab: that
- *  coexistence is the point. */
+ *  only way anything reaches a preview. */
 export function openPreview(target: PreviewTarget) {
   const current = $previewTabs.get()
-  const sessionId = $focusedStoredSessionId.get() ?? undefined
-  const id = target.kind === 'url' ? browserTabId(current) : previewTabId(target, sessionId)
+  const id = target.kind === 'url' ? browserTabId(current) : previewTabId(target)
   const index = current.findIndex(tab => tab.id === id)
-  const existing =
-    index === -1 && target.kind === 'file'
-      ? current.find(
-          tab => tab.pinned && tab.target.kind === 'file' && canonicalFileKey(tab.target) === canonicalFileKey(target)
-        )
-      : current[index]
-  const tab: PreviewTab = {
-    id,
-    target: withRenderMode(target, existing?.target),
-    sessionId: existing?.sessionId ?? sessionId,
-    pinned: existing?.pinned
-  }
+  const tab: PreviewTab = { id, target: withRenderMode(target, current[index]?.target) }
 
-  const replaceIndex = existing ? current.indexOf(existing) : -1
-
-  $previewTabs.set(replaceIndex === -1 ? [...current, tab] : current.map((item, i) => (i === replaceIndex ? tab : item)))
+  $previewTabs.set(index === -1 ? [...current, tab] : current.map((item, i) => (i === index ? tab : item)))
   noteExplicitPreviewOpen(id)
   selectRightRailTab(id)
 }
@@ -827,43 +693,6 @@ export function newBrowserTab() {
   selectRightRailTab(id)
 }
 
-/** Pin or unpin a preview tab. Pinned tabs render in EVERY session — the
- *  explicit cross-session workspace; unpinning returns it to its session
- *  (adopting the current one, and rekeying the file id, when the tab never
- *  had an owner). */
-export function setPreviewTabPinned(tabId: string, pinned: boolean): void {
-  const currentSession = $focusedStoredSessionId.get() ?? undefined
-  const activeId = $rightRailActiveTabId.get()
-  let newActiveId = activeId
-
-  $previewTabs.set(
-    $previewTabs.get().map(tab => {
-      if (tab.id !== tabId) {
-        return tab
-      }
-
-      const nextSession = tab.sessionId ?? (!pinned ? currentSession : undefined)
-      const nextId = tab.target.kind === 'file' ? previewTabId(tab.target, nextSession) : tab.id
-
-      if (tab.id === activeId) {
-        newActiveId = nextId
-      }
-
-      return { ...tab, id: nextId, pinned, sessionId: nextSession }
-    })
-  )
-
-  if (newActiveId !== activeId) {
-    selectRightRailTab(newActiveId)
-  }
-}
-
-/** Drop the tabs a deleted session opened. Pinned tabs survive — they belong
- *  to the workspace, not the session that opened them. */
-export function prunePreviewTabsForSession(sessionId: string): void {
-  $previewTabs.set($previewTabs.get().filter(tab => tab.pinned || tab.sessionId !== sessionId))
-}
-
 export function closeRightRailTab(tabId: string) {
   const current = $previewTabs.get()
   const index = current.findIndex(tab => tab.id === tabId)
@@ -894,18 +723,9 @@ export function closeRightRailTab(tabId: string) {
   }
 }
 
-/** Close the tab showing `source` in the CURRENT session, if one is open.
- *  Returns whether it closed. */
+/** Close the tab showing `source`, if one is open. Returns whether it closed. */
 export function closePreviewForSource(source: string): boolean {
-  const tab = $visiblePreviewTabs.get().find(item => item.target.source === source)
-
-  if (!tab) {
-    return false
-  }
-
-  closeRightRailTab(tab.id)
-
-  return true
+  return closePreviewMatching(source)
 }
 
 /** Close the first docked Browser tab whose current page URL matches.
@@ -963,14 +783,14 @@ export function closeBrowserPreviewMatchingLiveUrl(...candidates: string[]): boo
   return true
 }
 
-function closePreviewMatchingTabs(candidates: string[]): boolean {
+function closePreviewMatchingTabs(tabs: PreviewTab[], candidates: string[]): boolean {
   const queries = [...new Set(candidates.map(value => value.trim()).filter(Boolean))]
 
   if (queries.length === 0) {
     return false
   }
 
-  const tab = $visiblePreviewTabs.get().find(item => {
+  const tab = tabs.find(item => {
     const fields = [item.target.source, item.target.url, item.target.label]
 
     return queries.some(query => fields.includes(query))
@@ -989,13 +809,16 @@ function closePreviewMatchingTabs(candidates: string[]): boolean {
  *  Empty candidates are a no-op so a missed match cannot wipe the rail —
  *  closing the whole pane is `closeRightRail`. */
 export function closePreviewMatching(...candidates: string[]): boolean {
-  return closePreviewMatchingTabs(candidates)
+  return closePreviewMatchingTabs($previewTabs.get(), candidates)
 }
 
 /** Agent-driven close is scoped to the docked rail; an independent Browser
  *  window owns popped tabs and must not lose its backing state here. */
 export function closeDockedPreviewMatching(...candidates: string[]): boolean {
-  return closePreviewMatchingTabs(candidates)
+  const popped = $poppedBrowserTabIds.get()
+  const docked = $previewTabs.get().filter(tab => !popped.has(tab.id))
+
+  return closePreviewMatchingTabs(docked, candidates)
 }
 
 /** Artifact tabs can't outlive the registry they read from, so clearing it
diff --git a/apps/desktop/src/store/session-focus.ts b/apps/desktop/src/store/session-focus.ts
index e558ad0a89..cfd797bf24 100644
--- a/apps/desktop/src/store/session-focus.ts
+++ b/apps/desktop/src/store/session-focus.ts
@@ -4,8 +4,6 @@ import { findGroup, findGroupOfPane } from '@/components/pane-shell/tree/model'
 import { $activeTreeGroup, $layoutTree } from '@/components/pane-shell/tree/store'
 import { $workspaceMode } from '@/components/pane-shell/workspace-scope'
 
-import { $selectedStoredSessionId } from './session'
-
 // A chat surface: the primary's workspace or a session tile. Everything else a
 // zone can show — the sessions list, Files, Terminal, a preview tab — is chrome.
 const isChatPane = (paneId?: string): boolean => paneId === 'workspace' || Boolean(paneId?.startsWith('session-tile:'))
@@ -52,22 +50,3 @@ export const $focusedTreePaneId = computed(
     return active
   }
 )
-
-/** The stored id of the session the user is working in: a focused
- *  `session-tile:<storedId>` pane IS that session, anything else falls back to
- *  the route-driven primary selection.
- *
- *  Lives HERE, not in session-states.ts, because low-level stores (the preview
- *  rail) need it and session-states imports them — defining it there made
- *  `session-states` ⇄ `preview` a load cycle. The inputs (the layout tree and
- *  the primary selection) are both leaf stores, so every consumer can share one
- *  derivation without dragging session-states in. */
-export const TILE_PANE_PREFIX = 'session-tile:'
-
-export const $focusedSessionIsTile = computed($focusedTreePaneId, active =>
-  Boolean(active?.startsWith(TILE_PANE_PREFIX))
-)
-
-export const $focusedStoredSessionId = computed([$focusedTreePaneId, $selectedStoredSessionId], (active, selected) =>
-  active?.startsWith(TILE_PANE_PREFIX) ? active.slice(TILE_PANE_PREFIX.length) : selected
-)
diff --git a/apps/desktop/src/store/session-states.ts b/apps/desktop/src/store/session-states.ts
index b76dac383b..6b66f4c77f 100644
--- a/apps/desktop/src/store/session-states.ts
+++ b/apps/desktop/src/store/session-states.ts
@@ -73,7 +73,7 @@ import {
   setTurnStartedAt
 } from './session'
 import { secondaryProfileOwnerForEvent } from './session-event-provenance'
-import { $focusedSessionIsTile, $focusedStoredSessionId, TILE_PANE_PREFIX } from './session-focus'
+import { $focusedTreePaneId } from './session-focus'
 import { assertSessionOwnerResolved } from './session-owner-resolution'
 import {
   isSessionOwnerRoute,
@@ -1311,6 +1311,7 @@ export interface SessionTileWorkspaceScope {
 // set, with runtime bindings dropped so tiles re-resume on their own gateway.
 const TILES_KEY = 'hermes.desktop.sessionTiles.v2'
 const LEGACY_TILES_KEY = 'hermes.desktop.sessionTiles.v1'
+const TILE_PANE_PREFIX = 'session-tile:'
 const BOTS_TILE_BUCKET = '__bots_workspace__'
 
 /** Persisted placement — `dir` + strip slot (`before`) + dock `anchor` so a
@@ -3045,9 +3046,13 @@ export function reopenLastClosedTile(): void {
 // timer / model) reads these instead of the primary-only atoms.
 // ---------------------------------------------------------------------------
 
-// Re-exported from session-focus.ts so existing consumers keep their import
-// path; the definitions live there (see the note on that module).
-export { $focusedSessionIsTile, $focusedStoredSessionId }
+export const $focusedSessionIsTile = computed($focusedTreePaneId, active =>
+  Boolean(active?.startsWith(TILE_PANE_PREFIX))
+)
+
+export const $focusedStoredSessionId = computed([$focusedTreePaneId, $selectedStoredSessionId], (active, selected) =>
+  active?.startsWith(TILE_PANE_PREFIX) ? active.slice(TILE_PANE_PREFIX.length) : selected
+)
 
 /** Every session currently OPEN as a surface: the primary's selection plus
  *  every tile's stored id. The sidebar highlights all of them (the focused one