docs: record the rail search in the architecture invariants (#580)

CLAUDE.md gained a rule for the rail's Search sessions box and linked it
to architecture-invariants#session-list-layout-header-strip-vs-left-sidebar,
which said nothing about it, and the "Collapse is per-device" bullet under
Owner tab layouts had an exception it did not record.

- Session list layout: one paragraph on the shared _applyTabListFilter()
  over the pure CodemanTabSearch (classes only, layout-scoped hide rules,
  rail matches the name and the sidebar name + folder, locale-independent
  lower-casing), the alert-row keep (owner decision), the data-total count
  restore, the tree walk and roving-stop fix-up, the projection opening
  every group, the connector redraw, the global Escape claim, no drag
  while searching, and the reset off the rail.
- Owner tab layouts: the collapse bullet notes that a search draws every
  group open and refuses toggles without writing the stored set.
- CLAUDE.md: the Escape claim and the connector redraw as one clause on
  the existing rail search rule.

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

CLAUDE.md

@@ -337,7 +337,7 @@ Frontend JS modules have `@fileoverview` with `@dependency`/`@loadorder` tags. L
 
 **Mobile tab strip scrolling** (issue #257): under 768px the tab strip scrolls horizontally, so the active tab must be kept reachable. `_updateActiveTabImmediate()` reveals it via `computeTabScrollLeft()` (constants.js, rect math on the strip's own `scrollLeft`, never `scrollIntoView()`, which scrolls the document under the fixed header); `_fullRenderSessionTabs()` must restore `scrollLeft` across rebuilds and re-reveal only when the active tab changed (`_lastRenderedActiveTabId`) or, grouped by state, the ACTIVE tab moved to another state band (`_noteActiveTabBand()`, both render paths, scrolling row only; another tab's move never scrolls). ⚠️ The phone-block `min-width` on `.session-tab.active .tab-name` keeps the tab's centre off the gear/close icons, sized for numberless tabs 10+ (floor 40px); do not shrink it. ⚠️ Never reintroduce hoisting the active session to the front of the strip. Tests: `test/mobile-tab-tap-zones.test.ts`, `test/tab-triage.test.ts`. → [architecture-invariants#mobile-tab-strip-scrolling](docs/architecture-invariants.md#mobile-tab-strip-scrolling)
 
-**Session list layout: header strip or left sidebar** (`sessionListLayout`, default `header`; per-device via `displayKeys`, also in `SettingsUpdateSchema`): the list can move into a collapsible `<aside>` (Alt+B, `toggleSessionSidebar`) or, via `tabOrientation`, a resizable vertical `#tabRail` (desktop/tablet only). ⚠️ There is ONE `#sessionTabs`, MOVED between hosts, never a second list: `applySessionListLayout()` runs first, then `applyTabOrientation()`, both BEFORE `applyTabWrapSettings()`, and both arm/disarm `_startSidebarRichClock()`. ⚠️ Axis decisions use `_isVerticalTabList()`, never `isSessionSidebarActive()` alone. ⚠️ Rich rows share one gate, `isRichTabRows()`; rich CSS pairs sidebar+rail with comma-grouped selectors, never `:is()`, and card rules stay rail-scoped. ⚠️ Rail sort (`tabRailSort`, default `activity`) is the flex `order` property only, never a DOM reorder; the arrow-key walk alone follows computed `order`. ⚠️ Leaving sidebar mode clears `_sidebarFilter`; the handheld overlay drawer is `inert` when closed, the docked rail never. ⚠️ The rail's **Search sessions** box (`setTabRailSearch`, in memory only) and the sidebar filter share ONE row filter, `_applyTabListFilter()` over the pure `CodemanTabSearch` (constants.js): classes only, never a reorder or layout write; the rail matches the name, the sidebar name + folder. ⚠️ A session row with a tab alert (`tabAlerts`, red or yellow) is never hidden by either box: it goes in as `keep: true`, counts toward its group (which stays on screen) but not toward `matchCount`. While it runs `_projectTabGroups()` projects every group open (a collapsed group's rows are not in the DOM) and `toggleTabGroupCollapsed()` refuses, leaving the stored collapse untouched, and neither rail drag starts (owner decision: a drop is saved for every device, relative to rows the search hides; refused in `dragstart` and `_onTabLayoutPointerDown`, never via `draggable`, since a keystroke does not re-render); `applyTabOrientation()` clears it off the rail. Tests: `test/tab-rail-search.test.ts`, `test/tab-rail-search.browser.test.ts`. → [architecture-invariants#session-list-layout-header-strip-vs-left-sidebar](docs/architecture-invariants.md#session-list-layout-header-strip-vs-left-sidebar)
+**Session list layout: header strip or left sidebar** (`sessionListLayout`, default `header`; per-device via `displayKeys`, also in `SettingsUpdateSchema`): the list can move into a collapsible `<aside>` (Alt+B, `toggleSessionSidebar`) or, via `tabOrientation`, a resizable vertical `#tabRail` (desktop/tablet only). ⚠️ There is ONE `#sessionTabs`, MOVED between hosts, never a second list: `applySessionListLayout()` runs first, then `applyTabOrientation()`, both BEFORE `applyTabWrapSettings()`, and both arm/disarm `_startSidebarRichClock()`. ⚠️ Axis decisions use `_isVerticalTabList()`, never `isSessionSidebarActive()` alone. ⚠️ Rich rows share one gate, `isRichTabRows()`; rich CSS pairs sidebar+rail with comma-grouped selectors, never `:is()`, and card rules stay rail-scoped. ⚠️ Rail sort (`tabRailSort`, default `activity`) is the flex `order` property only, never a DOM reorder; the arrow-key walk alone follows computed `order`. ⚠️ Leaving sidebar mode clears `_sidebarFilter`; the handheld overlay drawer is `inert` when closed, the docked rail never. ⚠️ The rail's **Search sessions** box (`setTabRailSearch`, in memory only) and the sidebar filter share ONE row filter, `_applyTabListFilter()` over the pure `CodemanTabSearch` (constants.js): classes only, never a reorder or layout write; the rail matches the name, the sidebar name + folder. ⚠️ A session row with a tab alert (`tabAlerts`, red or yellow) is never hidden by either box: it goes in as `keep: true`, counts toward its group (which stays on screen) but not toward `matchCount`. ⚠️ Escape in the rail box is claimed by the global capture-phase Escape branch (the box's own `onkeydown` runs after it, too late to stop `closeAllPanels()`), and a filter change that shows or hides anything redraws the connector lines, since a keystroke re-renders nothing. While it runs `_projectTabGroups()` projects every group open (a collapsed group's rows are not in the DOM) and `toggleTabGroupCollapsed()` refuses, leaving the stored collapse untouched, and neither rail drag starts (owner decision: a drop is saved for every device, relative to rows the search hides; refused in `dragstart` and `_onTabLayoutPointerDown`, never via `draggable`, since a keystroke does not re-render); `applyTabOrientation()` clears it off the rail. Tests: `test/tab-rail-search.test.ts`, `test/tab-rail-search.browser.test.ts`. → [architecture-invariants#session-list-layout-header-strip-vs-left-sidebar](docs/architecture-invariants.md#session-list-layout-header-strip-vs-left-sidebar)
 
 **Tab layouts** (`tabArrangement`, per-device, default `classic`; `state`/`case`/`ledger` are opt-in; Discussion #426): `state` (option C) splits the list into needs you / waiting / working / idle (idle is `quiet`: its heading stays as the row's anchor but draws no label; `tabStateOrder: 'urgent-last'` flips the order, needs you at the bottom): rows in the desktop header strip with left-aligned labels in a measured column (the brand sits over the strip's corner, so the rows after the first start under "Codeman"), sections in the flat rail and the sidebar, inline dividers on the tablet strip, group order with no headings on phones. `case` (option A) wraps each case's tabs in one `.tab-cluster` box and hides the `-<case>` of a generated name (`.tab-name-case`). `ledger` (option B) is a CSS-only grid on the desktop header strip. `classic` is the old strip. Pure cores: `CodemanTabTriage` and `CodemanTabClusters` (constants.js). ⚠️ `state` is the flex `order` property plus `aria-hidden` heading/break elements reconciled in place by `_syncTabTriageChrome()` after BOTH render paths, never a DOM reorder (a state change is an incremental pass). ⚠️ `case` boxes ARE a DOM grouping, so the incremental path rebuilds whenever `_tabClusterLayout().key` changes; membership follows `_mobileOverviewCaseFor()` like the home screens. ⚠️ Drag only reorders within a group or box (`_isTabDropAcrossGroups()`). ⚠️ Named groups in the vertical rail win over both groupings. ⚠️ `classic` must leave no trace (no headings, no inline order, no boxes, no name split), and the ledger must not change the markup. Tests: `test/tab-triage.test.ts`, `test/tab-clusters.test.ts`. → [architecture-invariants#tab-layouts-by-state-by-case-ledger](docs/architecture-invariants.md#tab-layouts-by-state-by-case-ledger)
 

docs/architecture-invariants.md

@@ -306,7 +306,7 @@ So: `_confirmIdle()` (session.ts) requires the pane to go quiet, and then asks t
 
 - **Grouped iff vertical AND the owner has at least one group.** No layout, a failed `GET` (newest-wins via `createLoadCoordinator`, retried at 5/10/20/40 s and then left to the next SSE init or `tab:layoutChanged`) or zero groups renders the flat rail unchanged; the horizontal strip, phones and the sidebar never group. ⚠️ Adopting a layout rebuilds the strip ONLY when the structure key changed (`_applyTabLayout`): the server announces a change on every session create/close and order PUT, and the key deliberately leaves the layout version out, so those announcements cost a flat rail nothing.
 - **A render layer, never an order source.** `sessionOrder` (the server-projected global order), Alt+N, Ctrl+Tab and the palette are untouched; a grouped session row is the flat row's markup, so its badge still names its Alt+N slot. Web tabs keep their slot after every session wherever their group puts them (`renderWebviewTab`).
-- **Collapse is per-device** (`codeman:tab-groups-collapsed` in localStorage, ids of deleted groups garbage-collected on adoption). A store that throws means all-expanded; a malformed stored VALUE reads as empty and is rewritten, so it can never disable collapse on that device for good. A collapsed group still SHOWS the active row, and `_updateActiveTabImmediate` falls through to a full render whenever the structure key changes, since a class toggle cannot reveal a hidden row.
+- **Collapse is per-device** (`codeman:tab-groups-collapsed` in localStorage, ids of deleted groups garbage-collected on adoption). A store that throws means all-expanded; a malformed stored VALUE reads as empty and is rewritten, so it can never disable collapse on that device for good. A collapsed group still SHOWS the active row, and `_updateActiveTabImmediate` falls through to a full render whenever the structure key changes, since a class toggle cannot reveal a hidden row. The one exception is the rail's **Search sessions** box (#580): while it holds text `_projectTabGroups()` passes `collapsedGroupIds: []`, so every group is DRAWN open and a match inside a collapsed one can show, and `toggleTabGroupCollapsed()` refuses; the stored set and its localStorage key are never written, so clearing the search puts the collapse back exactly as it was (see Session list layout, the rail search).
 - **A collapsed header carries the most urgent alert it hides** (`hiddenGroupAlerts()`, applied by `_syncTabGroupHeaderAlerts` on BOTH render paths, since alerts change without a rebuild), in the tab alert language: `tab-alert-action` red, `tab-alert-idle` yellow. A permission prompt behind a collapse must never be invisible.
 - **Lineage arcs to a collapse-hidden session anchor to its group header** (`lineage-line--proxied`); two endpoints proxied to one header draw nothing.
 - **The upstream HTML5 drag stays off in the grouped rail**: a flat-order drop cannot express a group move, and the server re-ranks within the old group. The grouped rail has its OWN pointer drag instead (`_bindTabLayoutPointerDrag`, mouse/pen only, bound once on the container): rows move before/after a row or into a group, a header drag reorders groups, and the drop maps to ONE operation through the pure `dropOperation()`. Escape cancels a drag, and the click that ends one is swallowed. ⚠️ A press is only captured once it moves 6 px, so its release can land outside the rail: `pointerup`/`pointercancel` are heard on `window` while a press is pending, a move with the primary button up cancels it, and a new press cancels any previous one. Without that a stale press became a phantom drag on the next hover, and a replaced drag left its capture-phase Escape listener behind, swallowing every Escape before the terminal saw it. The flat rail and the header strip keep the HTML5 drag untouched. For the same reason Ctrl+Shift+{ / } only swaps with a neighbour in the active session's own section (`_canSwapActiveTabWith`, reading the projection's `sectionByRef`): a cross-group swap moves nothing on the server, gets no `session:orderChanged` back, and would leave this client's `sessionOrder` and Alt+N targets out of step with every other device.
@@ -793,6 +793,20 @@ Further detail: with many sessions the horizontal strip stops being scannable, w
 
 ⚠️ Leaving sidebar mode **clears `_sidebarFilter`**: the filter box only exists in the aside, so a stale filter would hide sessions from the header strip with no reachable control to clear it. ⚠️ On handhelds the closed drawer keeps `display: flex`, so without `inert` + `aria-hidden` (`_isSessionSidebarOverlay()`) its filter box and ~4 tab stops per session stay in the tab order; the DOCKED desktop rail must never be inerted, its rows are still clickable.
 
+⚠️ **The rail's Search sessions box and the sidebar's filter box are ONE row filter** (#580): `applySidebarFilter(query)` sets `_sidebarFilter`, the rail box (`setTabRailSearch`, `#tabRailSearch` at the top of `#tabRail`) sets `_tabRailSearch`, and both run `_applyTabListFilter()`, which reads the rows the last render drew and applies the pure `CodemanTabSearch` (constants.js) as classes. Only one needle is ever live, because the rail and the sidebar never host `#sessionTabs` at the same time (`applyTabOrientation()` forces horizontal while the sidebar owns the list); off the rail and out of a reachable sidebar the needle is empty and every class comes off. The rules that keep it a view filter:
+
+- **Classes only.** `tab-filtered-out` on a row, and on a `.tab-layout-group` or `.tab-cluster` the filter emptied; never a reorder, a re-render per keystroke, a layout write or a request, so `sessionOrder`, the Alt+N badges, the server order and the tab layout never move. Both render paths end in `applySidebarFilter()`, which re-applies it. The hide rules are layout-scoped like the sidebar's original one (`html[data-tab-orientation='vertical'] .tab-rail ...` for rows, groups and case boxes; `html[data-session-list="sidebar"] ...` for rows and case boxes), so a leaked class can never hide anything on the header strip, which has no box to clear it from.
+- **Matching.** The rail matches the NAME only (`.tab-name`'s `data-full-name`, a web tab's title, never a URL or folder); the sidebar keeps its name + working directory. Trimmed, case-insensitive substring, lower-cased with `toLowerCase()`, never `toLocaleLowerCase()` (a Turkish locale lowers "API" to "apı").
+- **A row with a tab alert is never hidden** (owner decision on #580, the collapsed-header promise again: a prompt waiting on you is never hidden by a view filter). The row goes into the core as `keep: true` when `tabAlerts` holds anything for it (red `action` or yellow `idle`); a kept row counts toward its section, so its group or case box stays on screen, but not toward `matchCount`, so "No sessions match" can show above a lone alerted row. Alerts come and go through `renderSessionTabs()`, whose tail re-runs the filter, so nothing else has to.
+- **Counts and the tree.** A section's count shows the rows left showing during a search and is restored from the `data-total` it stashed on first touch. In the grouped tree `_tabTreeItems()` skips a hidden group whole (header included), the filter tail re-runs `_applyTabTreePositions()` and moves the one roving stop off a hidden item, but only while a search hides something or right after one changed what shows (both render paths already set them over an unfiltered tree). Only the grouped rail is a tree; the flat rail stays a tablist.
+- **Collapsed groups.** A collapsed group's rows are not in the DOM, so a class cannot reveal them: the projection opens every group while the rail search runs (see Owner tab layouts), and `setTabRailSearch()` re-renders only when that changes the structure (`_isTabGroupStructureStale()`); every other keystroke only re-applies classes.
+- **Connectors.** Lineage lines and the subagent/ultracode connectors are anchored to row positions, and a keystroke re-renders nothing, so `_applyTabListFilter()` calls `updateConnectionLines()` whenever it actually showed or hid something (a row, a section, the state headings via `tabs-filtering`, the empty note). An unchanged re-apply at a render tail calls nothing, which keeps the incremental path's lineage gate meaningful.
+- **Escape.** The global key handler runs in the CAPTURE phase on `document`, before the box's inline `onkeydown`, so a `stopPropagation()` there comes too late: the global Escape branch claims an Escape whose target is `#tabRailSearch` while the box holds text (beside the group menu, the grouped-rail drag and the Tiles count menu) and routes it to `handleTabRailSearchKeydown()`. Without that, clearing the search also collapsed the Monitor and Subagents panels. An empty box leaves Escape to the global handler.
+- **No drag while searching** (owner decision): a drop is saved for every device, relative to rows the search hides. Both rail drags refuse in their start handlers (`_onTabLayoutPointerDown`, the flat rail's `dragstart`), never by flipping `draggable`, which only a render would restore.
+- **In memory only, cleared off the rail.** The text is never persisted or sent. `applyTabOrientation()` calls `_resetTabRailSearch()` before its render when the list leaves the vertical rail, the same reason leaving sidebar mode clears `_sidebarFilter`.
+
+Tests: `test/tab-rail-search.test.ts` (gate) and `test/tab-rail-search.browser.test.ts` (browser suite, not in the gate; it installs the real `setupEventListeners()` so the capture-before-inline Escape order is the shipped one).
+
 ⚠️ **The detailed RAIL additionally wears the home rail's CARD, and the detailed SIDEBAR deliberately does not**: the rail is an occasional, resizable list you scan, the sidebar is a permanently-docked nav column where 20 stacked cards read as a wall — so the card rules are RAIL-SCOPED and were NOT added to the comma-grouped selectors above, which is the one-line change that would silently restyle the sidebar. Card state accents reuse `home-sessions-blink-red`/`-yellow` rather than declaring a second pair, and every state dot rule excludes `.tab-alert-action`/`.tab-alert-idle` by hand, because those alert rules are only (0,3,0) and the rail's are (0,5,1)+. There is no `.active` rule in that block on purpose: `.session-tab.active` already paints border/background/box-shadow `!important`.
 
 ⚠️ **Row ORDER is a third rail attribute** (`tabRailSort: 'activity'|'manual'`, `data-tab-rail-sort`, default **activity**): a sorted rail answers the home screens' question with the home screens' answer, `CodemanSessionOrder` over rows classified by `_mobileOverviewState` (`_tabRailSortOrder` in app.js). ⚠️ **It is applied as the flex `order` property, never by reordering the DOM**: `#sessionTabs` stays in `sessionOrder`, so the Alt+N badge (`_tabIdx`, which therefore does NOT run 1,2,3 down a sorted rail — it names a shortcut, not a position), drag-and-drop, the arrow-key walk, the sidebar filter and `_scrollActiveTabIntoView()` all keep reading the list they always read, and a session changing state moves ONE inline style instead of forcing the full rebuild that would restart every card's animation on every SSE tick. The incremental render path therefore has to re-apply it (a state flip adds no tab, so the full rebuild is never reached) and an empty string is what clears it when sorting stops. ⚠️ Web tabs are pinned past the cards by a CSS `order: 9999` rather than an inline one, since `renderWebviewTabs()` emits the same markup for every layout; the flex default of 0 would interleave them among the sorted sessions. ⚠️ `setupTabDragHandlers()` sets `draggable="false"` and returns while sorting is on: the drop rewrites `sessionOrder` correctly and the sort then puts the card straight back, so the affordance would be a lie — `'manual'` is the way back to drag-reordering.