Open compact tool tabs as full-page surfaces

[brsbl]

Human comments

What was wrong

After the right panel became a shelf, every tab remained constrained to 298.67px. Selecting New Tab could update the tab strip while leaving Info content visible, so tool surfaces did not receive a usable phone-width canvas. A newly created terminal could also lose its persisted active selection while the terminal list caught up, causing the settled tab to fall back to the shelf.

What changed

• Let the active tab determine the compact presentation; the control that opened the panel does not independently choose shelf versus full-page.
• Keep Info in the compact right shelf.
• Expand every non-Info tab, including New Tab and tabs opened from it, from the right to a full-width surface above fixed app chrome.
• Render the available production tab and preserve its full-page presentation while persisted active selection catches up.
• Select and render New Tab's production content after its loading state settles.
• Close the right panel when the left navigation opens so compact surfaces cannot compete for the page.
• Replace substitute story markup and wrappers with the production shelf, panel, file preview, compact home, sidebar provider, and sidebar inset.

Compact presentation rules

The opener only selects or restores a tab. The active tab kind determines the panel geometry, and switching tabs changes that geometry immediately.

Trigger or active destination	Compact result
Open or select Info (thread-info)	Right shelf at 76vw. An unresolved or empty initial tab state also uses this safe fallback.
Open or select New Tab	Full-page at 100vw.
Open or select Terminal, Diff, Browser, file preview, plugin page, or any other non-Info tab	Full-page at 100vw.
Tap the right-panel toggle on an existing thread	Reopen the current tab: Info returns as a shelf; a non-Info tab returns full-page. If no tab has resolved, Info is the default shelf destination.
Tap the right-panel toggle on Home / new-thread compose	Create and select New Tab, so the panel opens full-page immediately.
Open the left navigation or close the right panel	Hide the right surface; this does not create a competing shelf.

No mobile-home, navigation-feedback, provider-cache, or base shelf behavior changes in this layer.

How you verified

• Chrome for Testing 151.0.7922.71 at 393×852 CSS px against exact final base ddaf081641b863e5c060f5bb5b5690439aaa3b7c and exact final head f06a2a7be2676edc878bc5808ae896a22784cca4.
• From the same production New Tab surface, chose Start terminal and waited for the real zsh tab and xterm subtree to settle with zero panel skeletons.
• Base: terminal remained in the 298.67px shelf at x=94.33 and the app stopped at x=-298.68. Head: the same terminal became a 393px full-page surface at x=0 and shifted the app completely to x=-393.
• Reproduced the active-selection race after terminal creation, then verified the final head keeps the settled production terminal full-page with no browser errors.
• Rechecked the exact final head in the branch web app on /projects/proj_m65y3vujaj/threads/thr_done, using one realistic environment-backed fixture, the same persisted AppPageHeader.tsx tab, the same populated Recent item, and the same viewport for both current-head captures. Only the active tab changed.
• Waited for production content before capture: Info rendered environment, branch, merge base, PR, commits, and changed files; New Tab rendered file search, production actions, and a Recent file opened through the production panel flow.
• Measured each production right-panel dialog subtree: Info settled at x=94.33, 298.67×852; New Tab settled at x=0, 393×852.
• In the Info shelf, both translated center-pane action regions computed hidden while the fixed sidebar toggle remained visible outside the inset.
• Full-page mode measured z=45 over fixed app chrome at z=40, while the production body-portaled tooltip remained z=50 and painted above the opaque tool page.
• Focus entered the panel, Tab and Shift+Tab stayed contained, the first Escape dismissed the nested tooltip without closing the tool page, and the second restored the exact right-panel trigger.
• Remote CI passed tests, typecheck, lint, both package smokes, and version gates on the exact final head. No local CI-equivalent command was run.

Current-head behavior: Info versus New Tab

The original evidence followed New Tab → Start terminal and captured the terminal endpoint. It proved that a non-Info tab became full-page, but Info was never selected, so the unchanged shelf exception was missing from the evidence.

Info tab — compact right shelf	New Tab — full-page surface

Original base/head width regression

This historical pair remains the original feature regression; the current-head pair above is the final-branch evidence.

Before — tool tab constrained to shelf	After — same tool tab full page

BB-Thread-ID: thr_wftu7bh9ez

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