Vertical tab rail: detailed rows (created / working / status), plus a rename-cancel fix

[Ark0N]

What this is

Codeman can put the session list in a vertical rail beside the terminal (App Settings → Appearance → Tabs → Tab Orientation: Vertical). Until now that rail showed a name per row and nothing else, even though the same information the home screen shows — when a session was created, how long it has been in the state it is in, and what that state is — already existed one surface over, on the rich left sidebar and on both home screens.

A docked column is not a tab strip: it has a row per session and width to spare, so a name is not the whole story it can tell. This PR gives the rail that row.

Before — name only:

1 rail-alpha
2 rail-beta
3 rail-gamma

After — the home screen's line, in the rail:

1 SH rail-alpha ⚙ × ⋯
📁 claudeman
CREATED 8m ago · WORKING 1m [working]

The setting

New per-device Vertical Rail Rows (tabRailDetail), directly under Tab Orientation:

Value	Meaning
Detailed (default)	created stamp, state duration, folder, status pill
Simple (name only)	exactly what the rail shipped with in 1.22.0

It only affects the vertical rail. The header tab strip is untouched, and the sidebar layouts keep their own sessionListLayout choice.

How it works

• One gate, one row model.isRichTabRows() = isSessionSidebarRich() || isTabRailRich(). The row model, markup and 20s in-place clock are the rich sidebar's existing ones, and the state classification comes from _mobileOverviewState() / _mobileOverviewSince(). The rail, the sidebar, the desktop home rail and the phone overview therefore cannot disagree about what "working" means, or about which timestamp measures it (a working pane repaints about once a second, so its duration is anchored on the turn's last Enter, not on last-activity).
• Detail rides on its own attribute (data-tab-rail-detail), the way the sidebar's does, so every existing html[data-tab-orientation='vertical'] rule keeps matching both variants with no edit. The pre-paint script stamps it, so a detailed rail does not flash through simple rows on load.
• A detail flip alone forces a render. The stamps line is emitted by the row template, not toggled by CSS, so flipping the setting has to rebuild the rows — and re-run applyTabWrapSettings(), the one owner of the folder line, which is now rail-aware.
• CSS twins are comma-grouped, never :is(). An :is() list takes its most specific argument's specificity, which would have lifted the sidebar arm from (0,3,1) to the rail's (0,5,1) and let those paint rules outrank things they never used to.

Width: three thresholds, all measured

At 256px the stamps line ellipsizes mid-word (CREA… · WORK…), which is the same reason the rich sidebar is 300px rather than 260px:

• A rail that has never been sized now opens at 320px — the existing Wide preset, so the settings select shows a named choice rather than "Custom". A width the user has actually chosen is never overridden.
• Below 288px the created stamp is dropped rather than truncated (tab-rail-tight, CSS only). What survives is the state duration, which is the number the list is ordered by, and its pill.
• Below 240px the rail drops back to simple rows entirely (tab-rail-compact, the existing threshold, which already re-renders).

Bug fixed along the way: Escape wiped session names

Not rail-specific, and it predates the rail — it reproduces in the plain header strip too. The inline tab rename's Escape handler cleared the input and blurred it, and the blur handler commits:

}elseif(e.key==='Escape'){input.value='';input.blur();// → finishRename({ commit: true }) with an empty value}

So cancelling a rename renamed the session to an empty string. Measured against a live server before the fix: ["rail-alpha", "", "rail-gamma"], with the tab falling back to its folder name. Escape now calls cancelRename(), which invalidates the edit so the blur that follows the input's removal is a no-op.

Testing

• npm test green (6101 passed) — includes new coverage in test/session-list-layout.test.ts for the rail-detail gate, the three ways it turns back off (simple / compact / horizontal), sidebar-wins, render-on-detail-flip, and the settings/schema/pre-paint/CSS plumbing.
• npm run test:browser -- test/inline-rename.test.ts green, including the new Escape regression — pinned by running it against the old code first, where it fails with expected [ '/api/sessions/esc-cancel/name' ] to deeply equal [].
• typecheck, lint, format:check, check:public-assets, check:frontend-syntax all clean.
• Verified live against a real server on an isolated instance (own data dir and tmux socket): detailed / simple / compact / header / sidebar variants, click-to-select, the ⋯ action menu, inline rename, Alt+N, the in-place stamp tick (same DOM node, new text), and a full settings-picker round-trip including a reload to confirm the pre-paint stamp.