Header: reopen the last tool view from the workspace strip

[thethinkmachine]

Adds a header button that reopens whichever tool view (Library, Algorithms, Grammar or Reference) was open last. It's the design we settled on after the header mock-ups.

What changed

Desktop. The button sits at the right end of the workspace tab strip, behind a thin divider. It looks like an unselected tab with an icon and the view's name: no box at rest, and the same hover as the tabs. The tooltip shows the view's shortcut key.

• The strip has a new outer frame (.tab-strip), and the border moved from .tab-bar to that frame. The tabs scroll inside the frame; the button stays fixed outside the scrolling part. With many workspaces the tabs scroll underneath it and it never scrolls out of view, which was the edge case found in the mock-ups.
• The tab-overflow chevron moved into the frame too, next to the tabs it lists. It's now drawn flat like the tabs instead of as a separate bordered box.

Phone (below 900px). There's no tab strip on phones, so the button shares a pill with the workspace switcher: the workspace name, a divider, then the button. Below 560px it shows the icon only. On phones the tool window opens below the header, so the button stays visible: it's highlighted while its view is open, and pressing it again closes the view.

Remembering the view. The last view is saved per browser in automata-aux-last. It shows Library until another view has been opened.

Nothing new was added to bridge.js: the click handler is attached in JS the first time the button is updated.

Testing

• npm test: 2626 passed, 0 failed. tests/aux-window.test.js adds five tests:
  • the button follows the last view, and its name, label and shortcut match it;
  • clicking opens the view, and on mobile a second press closes it;
  • the desktop and mobile buttons always show the same view;
  • the button and the chevron are inside the frame but outside the scrolling tabs, and the frame (not .tab-bar) holds the border;
  • the mobile pill contains both the workspace switcher and the button.
• npm run build succeeds.
• Checked in Chromium with no page errors at:
  • 1440px with 3 and 12 tabs, and 1000px with 12 tabs;
  • 390px and 700px on a touch phone, including opening and closing a view and the workspace menu still opening from the pill.
• The last view survives a reload.

🤖 Generated with Claude Code

https://claude.ai/code/session_01HPVKDwzQWjyqE1nApBQt6s

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Generated by Claude Code

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