[teamleaderleo]

This clears the "Scrollbars thin, one style" ratchet debt (scripts/cmux-next/check-scrollbars.sh, a warn-only base red in "cmux-next checks"), SCROLLBARS-THIN.

• SwiftUI: .thinScrollers() is added to the content of each ScrollView that lacked it:
  • HomeGroupInfoView (members, add contacts)
  • ChiefMemoryInspectorView (lines, detail)
  • BrowserDownloadsPopup
  • VaultListView
  • WorkspaceTodoPageView, which now imports CmuxNextDesign
• AppKit: ExtensionsMenuView and SidebarPullRequestCard no longer force scrollerStyle = .overlay. Both now call SystemScrollers.follow, as the other browser panels do. It sets the same overlay, auto-hiding style (vertical only, so there is no ThinScroller swap) and keeps that style after a "Show scroll bars" change. The commit carries Sidebar-Look: no visual change for the sidebar card.
• Gallery: BackgroundActivity.gallery.css drops its custom scrollbar-color.
• Not in this PR:
  • ReportsBasketView and ReportsBasketDetail are left to cmux NEXT feed: the Labs reports basket is AppKit (No new SwiftUI) #25031, which ports them to AppKit.
  • The AgentCLIIntentLedger List( false positive is fixed in the checker in fix(cmux-next checks): pre-push gate fixture, manifest reader, Browser waivers, scrollbar List false positive (base reds) #25032.

On the tip, check-scrollbars.sh drops from 14 hits to those 3.

Compile: cmux-ci compile-check --app passed at e9e563e (job 4be662e85a3c9f6433af75ea). The final head only changes followThin to follow.

No capture: every surface here uses the overlay scroller, which is hidden at rest; before and after stills are the same.

Screenshots: none attached. Every surface here uses the overlay scroller, which is hidden at rest, so before and after stills are the same. None of the capture states (cmux-ci capture --list-states) opens these surfaces. What changes is that these scrollers now follow the shared thin style while scrolling and under "Show scroll bars: Always".

Risk: low. The changes are view modifiers and scroller setup, with no data or layout logic. The .thinScrollers() probe is a background view that takes no hits.

🤖 Generated with Claude Code

Agent session: cosmic-gray

[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review caa5183: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr25051 -f ref=leo/next-thin-scrollers-rest -f platform=macos -f backend_mode=local

Gallery before/after for caa5183: the capture produced no images (run).

red: cmux-next checks (god files, concurrency, crash safety, l10n); no finished base run on e61cd8d to compare; do not merge until green; see lane-rules

Tour of caa5183b2c (run)

The path-selected recorder failed for core-after, core-before; see the run artifact and failed manifests.

Path-selected interactions

Interaction

Changed paths

core

Packages/macOS/CmuxNext/Sources/CmuxNextApp/Checklist/WorkspaceTodoPageView.swift Packages/macOS/CmuxNext/Sources/CmuxNextApp/Handlers/BrowserDownloadsPopup.swift Packages/macOS/CmuxNext/Sources/CmuxNextApp/Vault/VaultListView.swift Packages/macOS/CmuxNext/Sources/CmuxNextBrowser/UI/ExtensionsMenu/ExtensionsMenuView.swift Packages/macOS/CmuxNext/Sources/CmuxNextChiefMemory/ChiefMemoryInspectorView.swift Packages/macOS/CmuxNext/Sources/CmuxNextHome/Conversations/HomeGroupInfoView.swift Packages/macOS/CmuxNext/Sources/CmuxNextSidebar/Views/SidebarPullRequestCard.swift

Core UI (before): FAILED — 16 ok, 3 failed, 1 unavailable

Video (mp4)

#	Step	Result	Command
1	Launch	ok
2	New workspace	ok	cmux workspace new --name Tour
3	Type in the terminal	ok	cmux workspace name:Tour screen current pane current tab current terminal current write --text "echo hello from the cmux-next tour\r"
4	A command reports progress: tab loading spinner	ok	cmux workspace name:Tour screen current pane current tab current terminal current write --text "clear; printf '\\033]9;4;3\\007'; sleep 900\r"
5	Split right	failed: exited 1	cmux action run splitRight
6	Split down	failed: exited 1	cmux action run splitDown
7	New terminal tab	failed: exited 1	cmux action run newSurface
8	Browser tab	ok	cmux tab new-browser --url https://example.com
9	Hide the sidebar	ok	cmux action run toggleSidebar
10	Show the sidebar	ok	cmux action run toggleSidebar
11	Notification	ok	cmux notify --title Tour --body "Hello from CI"
12	Notifications panel	ok	cmux action run showNotifications
13	Agent chat	ok	cmux agent new-chat
14	Agent workspace	ok	cmux workspace new --name Agent
15	Agent starts	ok	cmux workspace name:Agent screen current pane current tab current terminal current write --text "clear; printf '\\033]7501;state=working\\033\\\\'; sleep 8; printf '\\033]7501;state=done\\033\\\\'; sleep 900\r"
16	An agent works: row working spinner	ok	cmux workspace new --name Notes
17	The agent finishes: done mark in the spinner's place	ok
18	Session tree: keycaps on the first rows	ok	cmux settings set sidebar.sessionTree true
19	Session tree back off for later tours	ok	cmux settings set sidebar.sessionTree false
20	Profile menu	unavailable: exited 1 (the menu shot needs a screen capture route)	cmux action run sidebar.profileMenu

Failed steps:

5. Split right


6. Split down


7. New terminal tab

Screenshots (12)

1. Launch


2. New workspace


3. Type in the terminal


4. A command reports progress: tab loading spinner


8. Browser tab


9. Hide the sidebar


11. Notification


12. Notifications panel


13. Agent chat


16. An agent works: row working spinner


17. The agent finishes: done mark in the spinner's place


18. Session tree: keycaps on the first rows

### Core UI \(after\): FAILED — 16 ok, 3 failed, 1 unavailable

Video (mp4)

#	Step	Result	Command
1	Launch	ok
2	New workspace	ok	cmux workspace new --name Tour
3	Type in the terminal	ok	cmux workspace name:Tour screen current pane current tab current terminal current write --text "echo hello from the cmux-next tour\r"
4	A command reports progress: tab loading spinner	ok	cmux workspace name:Tour screen current pane current tab current terminal current write --text "clear; printf '\\033]9;4;3\\007'; sleep 900\r"
5	Split right	failed: exited 1	cmux action run splitRight
6	Split down	failed: exited 1	cmux action run splitDown
7	New terminal tab	failed: exited 1	cmux action run newSurface
8	Browser tab	ok	cmux tab new-browser --url https://example.com
9	Hide the sidebar	ok	cmux action run toggleSidebar
10	Show the sidebar	ok	cmux action run toggleSidebar
11	Notification	ok	cmux notify --title Tour --body "Hello from CI"
12	Notifications panel	ok	cmux action run showNotifications
13	Agent chat	ok	cmux agent new-chat
14	Agent workspace	ok	cmux workspace new --name Agent
15	Agent starts	ok	cmux workspace name:Agent screen current pane current tab current terminal current write --text "clear; printf '\\033]7501;state=working\\033\\\\'; sleep 8; printf '\\033]7501;state=done\\033\\\\'; sleep 900\r"
16	An agent works: row working spinner	ok	cmux workspace new --name Notes
17	The agent finishes: done mark in the spinner's place	ok
18	Session tree: keycaps on the first rows	ok	cmux settings set sidebar.sessionTree true
19	Session tree back off for later tours	ok	cmux settings set sidebar.sessionTree false
20	Profile menu	unavailable: exited 1 (the menu shot needs a screen capture route)	cmux action run sidebar.profileMenu

Failed steps:

5. Split right


6. Split down


7. New terminal tab

Screenshots (12)

1. Launch


2. New workspace


3. Type in the terminal


4. A command reports progress: tab loading spinner


8. Browser tab


9. Hide the sidebar


11. Notification


12. Notifications panel


13. Agent chat


16. An agent works: row working spinner


17. The agent finishes: done mark in the spinner's place


18. Session tree: keycaps on the first rows

_{Tours are data in scripts/cmux-next/media/tours: add a step or a tour file to show your feature.}

[teamleaderleo]

Owned by claude-sr2/base-red-checks on cosmic-gray · session

[blacksmith-sh]

Found 85 test failures on Blacksmith runners:

Failures

Test	View Logs
/tmp/tmpcl_qswq4/summary-missing.json (live):/summary-missing.json (live):	View Logs
/tmp/tmpoiwr86o7/summary-fail.json (live):/summary-fail.json (live):	View Logs
[new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows/ [new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows	View Logs
[new_workspaces] the window draws no frames/[new_workspaces] the window draws no frames	View Logs
[tabs] debug.tab_switch timed 0 of 40 switches/ [tabs] debug.tab_switch timed 0 of 40 switches	View Logs
[tabs] the window draws no frames/[tabs] the window draws no frames	View Logs
bundle-cmux-tui.sh failed (/tmp/tmp.neidJdKjBA/new/cmux-tui)	View Logs
bundle-cmux-tui.sh failed (/tmp/tmp.neidJdKjBA/new/cmux-tui)	View Logs
bundle-cmux-tui.sh failed (tree, /tmp/tmp.yaUIgNsLOl/build/one/cmux-tui)	View Logs
bundle-cmux-tui.sh failed (tree, /tmp/tmp.yaUIgNsLOl/build/one/cmux-tui)	View Logs

...and 75 more test failures. View all on Blacksmith: run 40154415785, run 40154415837, run 40154415885

^{Need help on this PR? Tag @codesmith-bot with what you need.}

[teamleaderleo]

Bead cx-15a7e created for this PR by the cmux coordinator.

[github-actions]

Shipped in:

• cmux NEXT nightly 1.0.0-nightly.4015783372101 (354e937914)
• cmux NEXT nightly 1.0.0-nightly.4015912756102 (35b0693091)