feat(web): add optional compact sidebar rail

apps/web/src/components/AppSidebarLayout.tsx

@@ -14,7 +14,11 @@ import { getLocalStorageItem, removeLocalStorageItem } from "../hooks/useLocalSt
 import { resolveShortcutCommand, shortcutLabelForCommand } from "../keybindings";
 import { cn, isMacPlatform } from "../lib/utils";
 import { primaryServerKeybindingsAtom } from "../state/server";
-import { useEnvironmentIdentificationMode, useLegacySidebarEnabled } from "../hooks/useSettings";
+import {
+  useCompactSidebarEnabled,
+  useEnvironmentIdentificationMode,
+  useLegacySidebarEnabled,
+} from "../hooks/useSettings";
 import {
   PanelAnimationSuppressionProvider,
   usePanelAnimationSettings,
@@ -144,6 +148,7 @@ function ProjectProjectionRetention() {
 export function AppSidebarLayout({ children }: { children: ReactNode }) {
   const navigate = useNavigate();
   const legacySidebarEnabled = useLegacySidebarEnabled();
+  const compactSidebarEnabled = useCompactSidebarEnabled();
   const { active: panelAnimationsActive, durationMs: panelAnimationDurationMs } =
     usePanelAnimationSettings();
   // Settings routes show the settings nav in place of whichever thread
@@ -229,7 +234,7 @@ export function AppSidebarLayout({ children }: { children: ReactNode }) {
         <ProjectProjectionRetention />
         <Sidebar
           side="left"
-          collapsible="offcanvas"
+          collapsible={compactSidebarEnabled ? "icon" : "offcanvas"}
           data-app-sidebar=""
           className="border-r border-sidebar-border bg-sidebar text-sidebar-foreground"
           resizable={{

apps/web/src/components/LegacySidebar.tsx

@@ -199,7 +199,11 @@ import { SidebarChromeFooter, SidebarChromeHeader } from "./sidebar/SidebarChrom
 import { useCopyToClipboard } from "~/hooks/useCopyToClipboard";
 import { useIsMobile } from "~/hooks/useMediaQuery";
 import { CommandDialogTrigger } from "./ui/command";
-import { useClientSettings, useUpdateClientSettings } from "~/hooks/useSettings";
+import {
+  useClientSettings,
+  useCompactSidebarEnabled,
+  useUpdateClientSettings,
+} from "~/hooks/useSettings";
 import { primaryServerKeybindingsAtom } from "../state/server";
 import {
   derivePhysicalProjectKey,
@@ -1194,7 +1198,9 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
   const router = useRouter();
   const queuePendingFileDrop = useSidebarPendingFileDropStore((s) => s.queuePendingFileDrop);
   const clearPendingFileDrop = useSidebarPendingFileDropStore((s) => s.clearPendingFileDrop);
-  const { isMobile, setOpenMobile } = useSidebar();
+  const { isMobile, setOpenMobile, state, setOpen } = useSidebar();
+  const compactSidebarEnabled = useCompactSidebarEnabled();
+  const isCompact = compactSidebarEnabled && !isMobile && state === "collapsed";
   const markThreadUnread = useUiStateStore((state) => state.markThreadUnread);
   const setProjectExpanded = useUiStateStore((state) => state.setProjectExpanded);
   const toggleThreadSelection = useThreadSelectionStore((state) => state.toggleThread);
@@ -1445,10 +1451,13 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
       if (useThreadSelectionStore.getState().hasSelection()) {
         clearSelection();
       }
-      setProjectExpanded(projectPreferenceKeys, !projectExpanded);
+      setProjectExpanded(projectPreferenceKeys, isCompact || !projectExpanded);
+      if (isCompact) setOpen(true);
     },
     [
       clearSelection,
+      isCompact,
+      setOpen,
       dragInProgressRef,
       projectExpanded,
       projectPreferenceKeys,
@@ -1465,9 +1474,17 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
       if (dragInProgressRef.current) {
         return;
       }
-      setProjectExpanded(projectPreferenceKeys, !projectExpanded);
+      setProjectExpanded(projectPreferenceKeys, isCompact || !projectExpanded);
+      if (isCompact) setOpen(true);
     },
-    [dragInProgressRef, projectExpanded, projectPreferenceKeys, setProjectExpanded],
+    [
+      dragInProgressRef,
+      isCompact,
+      projectExpanded,
+      projectPreferenceKeys,
+      setOpen,
+      setProjectExpanded,
+    ],
   );
 
   const handleProjectButtonPointerDownCapture = useCallback(
@@ -2359,8 +2376,10 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
     <>
       <div className="group/project-header relative">
         <SidebarMenuButton
+          tooltip={project.displayName}
+          aria-label={project.displayName}
           ref={isManualProjectSorting ? dragHandleProps?.setActivatorNodeRef : undefined}
-          className={`pr-8 group-hover/project-header:bg-sidebar-row-hover group-hover/project-header:text-sidebar-foreground max-sm:pr-14 ${
+          className={`pr-8 group-hover/project-header:bg-sidebar-row-hover group-hover/project-header:text-sidebar-foreground max-sm:pr-14 group-data-[collapsible=icon]:justify-center ${
             isManualProjectSorting ? "cursor-grab active:cursor-grabbing" : ""
           }`}
           {...(isManualProjectSorting && dragHandleProps ? dragHandleProps.attributes : {})}
@@ -2370,7 +2389,7 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
           onKeyDown={handleProjectButtonKeyDown}
           onContextMenu={handleProjectButtonContextMenu}
         >
-          {!projectExpanded && projectStatus ? (
+          {isCompact ? null : !projectExpanded && projectStatus ? (
             <Tooltip>
               <TooltipTrigger
                 render={
@@ -2401,7 +2420,7 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
           <span className="flex shrink-0">
             <ProjectFavicon project={project} />
           </span>
-          <span className="flex min-w-0 flex-1 items-center gap-2">
+          <span className="flex min-w-0 flex-1 items-center gap-2 group-data-[collapsible=icon]:hidden">
             <span className="truncate text-sm font-medium text-sidebar-foreground/90">
               {project.displayName}
             </span>
@@ -2415,7 +2434,7 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
         {/* Environment badge – visible by default, crossfades with the
             "new thread" button on hover using the same pointer-events +
             opacity pattern as the thread row archive/timestamp swap. */}
-        {project.environmentPresence === "remote-only" && (
+        {!isCompact && project.environmentPresence === "remote-only" && (
           <Tooltip>
             <TooltipTrigger
               render={
@@ -2441,7 +2460,7 @@ const SidebarProjectItem = memo(function SidebarProjectItem(props: SidebarProjec
         <Tooltip>
           <TooltipTrigger
             render={
-              <div className="pointer-events-none absolute top-[calc(50%+1px)] right-0.5 -translate-y-1/2 opacity-0 transition-opacity duration-150 max-sm:pointer-events-auto max-sm:opacity-100 group-hover/project-header:pointer-events-auto group-hover/project-header:opacity-100 group-focus-within/project-header:pointer-events-auto group-focus-within/project-header:opacity-100">
+              <div className="pointer-events-none absolute top-[calc(50%+1px)] right-0.5 -translate-y-1/2 opacity-0 transition-opacity duration-150 max-sm:pointer-events-auto max-sm:opacity-100 group-hover/project-header:pointer-events-auto group-hover/project-header:opacity-100 group-focus-within/project-header:pointer-events-auto group-focus-within/project-header:opacity-100 group-data-[collapsible=icon]:hidden">
                 <button
                   type="button"
                   aria-label={`Create new thread in ${project.displayName}`}
@@ -2674,7 +2693,7 @@ function LocalSecondaryStatus() {
   }
 
   return (
-    <SidebarGroup className="px-2 pt-2 pb-0">
+    <SidebarGroup className="px-2 pt-2 pb-0 group-data-[collapsible=icon]:hidden">
       {connecting.length > 0 ? (
         <Alert
           variant="default"
@@ -2978,14 +2997,16 @@ const SidebarProjectsContent = memo(function SidebarProjectsContent(
                 render={
                   <SidebarMenuButton
                     className="focus-visible:ring-0"
+                    tooltip="Search"
+                    aria-label="Search"
                     data-testid="command-palette-trigger"
                   />
                 }
               >
                 <SearchIcon />
-                <span className="flex-1 truncate">Search</span>
+                <span className="flex-1 truncate group-data-[collapsible=icon]:hidden">Search</span>
                 {commandPaletteShortcutLabel ? (
-                  <Kbd className="h-4 min-w-0 rounded-sm px-1.5 text-[10px]">
+                  <Kbd className="h-4 min-w-0 rounded-sm px-1.5 text-[10px] group-data-[collapsible=icon]:hidden">
                     {commandPaletteShortcutLabel}
                   </Kbd>
                 ) : null}
@@ -2996,7 +3017,7 @@ const SidebarProjectsContent = memo(function SidebarProjectsContent(
       }
     >
       {showArm64IntelBuildWarning && arm64IntelBuildWarningDescription ? (
-        <SidebarGroup className="px-2 pt-2 pb-0">
+        <SidebarGroup className="px-2 pt-2 pb-0 group-data-[collapsible=icon]:hidden">
           <Alert variant="warning" className="rounded-2xl border-warning/40 bg-warning/8">
             <TriangleAlertIcon />
             <AlertTitle>Intel build on Apple Silicon</AlertTitle>
@@ -3020,17 +3041,21 @@ const SidebarProjectsContent = memo(function SidebarProjectsContent(
       ) : null}
       <LocalSecondaryStatus />
       <SidebarGroup className="px-2 py-2">
-        <div className="mb-1 flex items-center justify-between pl-2 pr-1.5">
-          <span className="text-xs font-medium text-sidebar-muted-foreground/80">Projects</span>
+        <div className="mb-1 flex items-center justify-between pl-2 pr-1.5 group-data-[collapsible=icon]:justify-center group-data-[collapsible=icon]:px-0">
+          <span className="text-xs font-medium text-sidebar-muted-foreground/80 group-data-[collapsible=icon]:hidden">
+            Projects
+          </span>
           <div className="flex items-center gap-1">
-            <ProjectSortMenu
-              projectSortOrder={projectSortOrder}
-              threadSortOrder={threadSortOrder}
-              threadPreviewCount={threadPreviewCount}
-              onProjectSortOrderChange={handleProjectSortOrderChange}
-              onThreadSortOrderChange={handleThreadSortOrderChange}
-              onThreadPreviewCountChange={handleThreadPreviewCountChange}
-            />
+            <div className="group-data-[collapsible=icon]:hidden">
+              <ProjectSortMenu
+                projectSortOrder={projectSortOrder}
+                threadSortOrder={threadSortOrder}
+                threadPreviewCount={threadPreviewCount}
+                onProjectSortOrderChange={handleProjectSortOrderChange}
+                onThreadSortOrderChange={handleThreadSortOrderChange}
+                onThreadPreviewCountChange={handleThreadPreviewCountChange}
+              />
+            </div>
             <Tooltip>
               <TooltipTrigger
                 render={
@@ -3127,7 +3152,9 @@ const SidebarProjectsContent = memo(function SidebarProjectsContent(
         )}
 
         {projectsLength === 0 && (
-          <div className="px-2 pt-4 text-center text-secondary-label text-xs">No projects yet</div>
+          <div className="px-2 pt-4 text-center text-secondary-label text-xs group-data-[collapsible=icon]:hidden">
+            No projects yet
+          </div>
         )}
       </SidebarGroup>
     </SidebarContent>

apps/web/src/components/Sidebar.drag.ts

@@ -103,6 +103,7 @@ export function createSidebarSortingStrategy(input: {
   snoozedThreadCount?: number;
   cardHeight?: number;
   slimHeight?: number;
+  compact?: boolean;
   /** Space each pinned boundary opens for its label while dragging. The
    * markers stay zero height at rest, so nothing is reserved until pickup. */
   boundaryLabelHeight?: number;
@@ -140,11 +141,14 @@ export function createSidebarSortingStrategy(input: {
       else slimHeight ??= rects[index]?.height;
       if (item.key !== active.key) groups[item.section].push(item);
     }
-    // Cards are 4.875rem + 0.25rem padding; slim rows/placeholders are h-9.
-    const scale =
-      slimHeight !== undefined ? slimHeight / 36 : (headerScale ?? (cardHeight ?? 82) / 82);
-    cardHeight ??= 82 * scale;
-    slimHeight ??= 36 * scale;
+    // Compact icons use h-7; expanded cards include their vertical padding.
+    const scale = input.compact
+      ? (cardHeight ?? slimHeight ?? 28) / 28
+      : slimHeight !== undefined
+        ? slimHeight / 36
+        : (headerScale ?? (cardHeight ?? 82) / 82);
+    cardHeight ??= (input.compact ? 28 : 82) * scale;
+    slimHeight ??= (input.compact ? 28 : 36) * scale;
     const labelHeight = (input.boundaryLabelHeight ?? 0) * scale;
     const group = groups[target.section];
     const order =