fix(tabs): state rows start under the brand, labels left-aligned (#426)

In the desktop header strip grouped by state, the brand leaves the flow
and sits over the strip's top-left corner, so every row after the first
starts at the left edge under "Codeman" instead of leaving that corner
empty. Labels are left-aligned in the measured column; the first row's
heading takes its natural width beside the brand (--tab-triage-brand,
kept by a ResizeObserver so no render pass reads layout for it).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/architecture-invariants.md

@@ -871,7 +871,7 @@ Tests: `test/terminal-touch-tap.test.ts`.
 
 **Tab layouts** (`tabArrangement`, per-device, default `state`; Discussion #426): App Settings → Appearance → Tabs → **Tab Layout**. Four values: `state` (option C), `case` (option A), `ledger` (option B) and `classic`, the strip as before. `<html data-tab-arrangement>` is stamped pre-paint and by `applyTabOrientation()`; the render paths read it through `isTabTriage()`, `isTabClusters()` and `isTabLedger()`. Named groups in the vertical rail (owner tab layouts, `_projectTabGroups()` non-null) win over both groupings, and the grouped tree renders as before.
 
-**By state.** The list is split into four groups: **needs you** (a permission or question dialog; a failed session joins it), **waiting** (idle prompt pending), **working**, **idle** (also ended sessions, an agent that exited inside a live pane, and web tabs). `tabStateOrder` (`urgent-first` default, `urgent-last`) decides which end they start from; only the group order flips, never the rows inside a group. The desktop header strip draws a row per group with its label right-aligned in a left gutter that `_sizeTabTriageGutter()` measures to the widest label on screen (re-measured only when the label text changes, and once on `document.fonts.ready`), so no row carries a fixed gutter's worth of empty space; the flat rail and the sidebar draw a section per group; the tablet strip (600-767px) keeps its scrolling row with the headings as inline dividers; phones keep their chip row in group order with the headings hidden (mobile.css). Classification is `_mobileOverviewState()` + `_mobileOverviewExit()`, the home screens' own; the fold into four groups and the order bands are pure in `CodemanTabTriage` (constants.js, `computeTabTriageLayout()`).
+**By state.** The list is split into four groups: **needs you** (a permission or question dialog; a failed session joins it), **waiting** (idle prompt pending), **working**, **idle** (also ended sessions, an agent that exited inside a live pane, and web tabs). `tabStateOrder` (`urgent-first` default, `urgent-last`) decides which end they start from; only the group order flips, never the rows inside a group. The desktop header strip draws a row per group with its label left-aligned in a column that `_sizeTabTriageGutter()` measures to the widest label on screen (re-measured only when the label text changes, and once on `document.fonts.ready`), so no row carries a fixed gutter's worth of empty space. The brand leaves the flow and sits over the strip's top-left corner (`.header:has(...)`), so the first row's heading (`.tab-triage-head--lead`, natural width) is pushed past it by `--tab-triage-brand` (a ResizeObserver keeps that width, so no render pass reads layout for it) and every later row starts at the edge, under "Codeman"; the flat rail and the sidebar draw a section per group; the tablet strip (600-767px) keeps its scrolling row with the headings as inline dividers; phones keep their chip row in group order with the headings hidden (mobile.css). Classification is `_mobileOverviewState()` + `_mobileOverviewExit()`, the home screens' own; the fold into four groups and the order bands are pure in `CodemanTabTriage` (constants.js, `computeTabTriageLayout()`).
 
 ⚠️ **By state is the flex `order` property, never a DOM reorder**, exactly like the sorted rail: `#sessionTabs` stays in `sessionOrder`, so the Alt+N badges, drag, the keyboard walk (which sorts by COMPUTED order) and the sidebar filter keep reading the list they always read. Each group owns a band of `TAB_TRIAGE_STRIDE` order values: its heading, its rows, its web tabs, then the row break that ends the header line. The headings and breaks are `aria-hidden` direct children of `#sessionTabs`, reconciled in place by `_syncTabTriageChrome()` after BOTH render paths, because a state change is an incremental pass and can still empty a group or fill a new one. Inside a header row tabs keep TAB order; a sorted rail ranks each section the way it ranks the flat rail. The header strip only wraps into rows on desktop, where `updateTabOverflowMode()` forces `tabs-auto-wrap`; the breaks only display in a wrapping strip, since a `flex-basis: 100%` break in a nowrap scroller would steal width.