fix(desktop): hide collapsed sidebar icon rail

[ButterBright]

Summary

Fixes the macOS traffic-light buttons so they no longer span the sidebar and main content area.

When collapsed, the sidebar now:

• Closes completely instead of leaving a 48px icon rail.
• Removes hidden sidebar controls from pointer and keyboard interaction.
• Keeps the titlebar restore action visible so the sidebar can be reopened.

Verification

Added Playwright coverage confirming that:

• The collapsed sidebar has a width of 0px.
• Sidebar navigation is hidden while collapsed.
• The titlebar restore action remains visible.
• The sidebar can be expanded again.

AI use

Select exactly one:

• No generative tool made a substantive contribution
• Generative tooling made a substantive contribution

Tool(s) and scope:

Investigated the collapsed-sidebar layout, implemented the CSS and Storybook updates, added targeted Playwright coverage.

Checklist

• Tests cover the change and fail without it
• Lint, format, typecheck and the affected suites pass locally

Does this PR entail a change in behavior?

• Yes — described under Summary above
• No

[Astro-Han]

Update on 1ffbc27c87:

Standards NO-GO (5 hard): missing real-window smoke (smoke:real-window), incomplete before/after evidence, missing AI-use declaration, incomplete PR template/branch naming. Code itself is Spec PASS — collapsed rail correctly hidden via visibility:hidden with restore action. CI test is still QUEUED — not green.

简体中文

因流程与验证材料缺失暂不通过。

[ButterBright]

Updated.

[Astro-Han]

Thanks, nice fix~ The e2e might need some fix since it changes the folding action. Can we take a look at the e2e test and fix these?

[Astro-Han]

Superseded — see the approving review for the final findings. (Trimmed: this pass raised a P1 about collapsed-state navigation that I later withdrew as incorrect.)

[Astro-Han]

Superseded — see the approving review for the final findings. (Trimmed: this pass raised a P1 about collapsed-state navigation that I later withdrew as incorrect.)

[Astro-Han]

Correction: the P1 I raised about collapsed-state navigation was wrong, and I withdrew it.

command-palette.tsx:59-65 registers mod+k at window level, and command-palette-commands.ts:252-284 routes to skills, mcp, scheduled-tasks and daily-review. So collapsed, 扩展 and 自动化 are reachable via ⌘K, 新任务 via ⌘N, 设置 via ⌘,. Only the WorkHub rail item and the update reminder lose an entry point, and WorkHub is off by default with a return path in the session view.

My mistake was checking the menu and titlebar and stopping there instead of enumerating setNavSelection callers.

[Astro-Han]

Approving. CSS mechanism and titlebar grid arithmetic verified; the earlier P1 is withdrawn (see the correction above).

P3s, non-blocking:

1. ensureSidebarExpanded (fixtures.ts:62-72) uses isVisible(), which does not auto-wait — six call sites inherit it, and it will produce flakes that look unrelated. Fix this one first. It also hard-codes strings that live in shell-copy.ts.
2. Four collapsed-state rules in sidebar.css (:130-132, :186-190, :209-211, :239-241) now style an invisible subtree; their comments still describe the 48px rail, as does session-sidebar-nav.tsx:191. Delete with the rail.
3. app-shell-chrome-actions.tsx:116-118 refers to a rail that no longer exists.
4. pointer-events: none is redundant with visibility: hidden.
5. visibility is not transitioned, so content vanishes on frame one while the wrapper eases 260px → 0.

Also worth stating in the body: the collapsed rail's six entries are gone and ⌘K/⌘N/⌘, carry them now.

AI use: Claude Code (Opus) assisted; I verified the CSS mechanism, grid arithmetic, and collapsed-state reachability myself. Nothing was rendered — the traffic-light claim rests on the author's screenshot.