Feat: Add collapsible shell

.gitignore

@@ -25,3 +25,5 @@ pnpm-debug.log*
 # Go build output
 tmp/
 bin/
+
+.cgcignore

Backend/internal/config/config.go

@@ -15,7 +15,6 @@ type Config struct {
 	LogLevel        string
 	WebPort         string
 	APIPort         string
-	WorkerPort      string
 	PostgresURL     string
 	ValkeyURL       string
 	ShutdownTimeout time.Duration
@@ -28,7 +27,6 @@ func Load() *Config {
 		LogLevel:        getEnv("LOG_LEVEL", "debug"),
 		WebPort:         getEnv("BACKEND_WEB_PORT", "8080"),
 		APIPort:         getEnv("BACKEND_API_PORT", "8081"),
-		WorkerPort:      getEnv("BACKEND_WORKER_PORT", "8082"),
 		PostgresURL:     getEnv("DATABASE_URL", "postgres://moku:moku_dev_password@localhost:5432/moku?sslmode=disable"),
 		ValkeyURL:       getEnv("VALKEY_URL", "redis://localhost:6379/0"),
 		ShutdownTimeout: getDurationEnv("BACKEND_SHUTDOWN_TIMEOUT", 10*time.Second),
@@ -43,8 +41,6 @@ func (c *Config) Address(serviceName string) string {
 		port = c.WebPort
 	case "api":
 		port = c.APIPort
-	case "worker":
-		port = c.WorkerPort
 	default:
 		port = c.WebPort
 	}

Env/.env.example

@@ -6,7 +6,6 @@ LOG_LEVEL=debug
 
 BACKEND_WEB_PORT=8080
 BACKEND_API_PORT=8081
-BACKEND_WORKER_PORT=8082
 BACKEND_SHUTDOWN_TIMEOUT=10s
 
 DATABASE_URL=postgres://moku:moku_dev_password@localhost:5432/moku?sslmode=disable

Frontend/src/components/shell/AppShell/AppShell.module.scss

@@ -23,6 +23,14 @@
   background: var(--color-surface);
 }
 
+.bodyRailCollapsed {
+  --rail-width: 0rem;
+}
+
+.bodySidebarCollapsed {
+  --sidebar-width: 0rem;
+}
+
 .railColumn {
   min-height: 0;
   display: flex;
@@ -97,7 +105,7 @@
   position: absolute;
   bottom: var(--space-3);
   left: calc(var(--space-1) + (var(--rail-width) * 0.1));
-  width: calc(var(--sidebar-width) + (var(--rail-width) * 0.9) - var(--space-2));
+  width: max(12rem, calc(var(--sidebar-width) + (var(--rail-width) * 0.9) - var(--space-2)));
   right: auto;
   z-index: calc(var(--z-modal) + 1);
   pointer-events: none;
@@ -112,6 +120,14 @@
     --rail-width: 5rem;
     --sidebar-width: 17.25rem;
   }
+
+  .bodyRailCollapsed {
+    --rail-width: 0rem;
+  }
+
+  .bodySidebarCollapsed {
+    --sidebar-width: 0rem;
+  }
 }
 
 @include respond-down(tablet) {
@@ -119,6 +135,58 @@
     --rail-width: 4.5rem;
     --sidebar-width: 13.25rem;
   }
+
+  .bodyRailCollapsed {
+    --rail-width: 0rem;
+  }
+
+  .bodySidebarCollapsed {
+    --sidebar-width: 0rem;
+  }
+}
+
+.bodyRailCollapsed .railColumn {
+  overflow: hidden;
+}
+
+.bodySidebarCollapsed .railColumn {
+  --rail-dock-clearance: 0rem;
+}
+
+.bodySidebarCollapsed:not(.bodyRailCollapsed) .railColumn {
+  --rail-bottom-offset: var(--space-3);
+}
+
+.bodySidebarCollapsed .sidebarColumn {
+  --sidebar-dock-clearance: 0rem;
+  display: none;
+  overflow: hidden;
+  border-left-width: 0;
+  border-top-width: 0;
+}
+
+.bodySidebarCollapsed .workspaceRegion {
+  grid-template-columns: minmax(0, 1fr);
+}
+
+.bodySidebarCollapsed .workspaceMain {
+  border-left-color: transparent;
+}
+
+.bodySidebarCollapsed:not(.bodyRailCollapsed) .workspaceMain {
+  border-top-width: 1px;
+  border-top-color: var(--shell-frame-border);
+  border-left-color: var(--shell-frame-border);
+  border-top-left-radius: var(--shell-top-left-radius);
+  box-shadow: none;
+}
+
+.bodySidebarCollapsed:not(.bodyRailCollapsed) .workspaceRegion::before {
+  display: none;
+}
+
+.bodySidebarCollapsed .sidebarDock {
+  display: none;
 }
 
 @include respond-down(mobile) {

Frontend/src/components/shell/AppShell/AppShell.tsx

@@ -11,6 +11,8 @@ import styles from "./AppShell.module.scss";
 
 export const AppShell = (): JSX.Element => {
 	const [themeState, setThemeState] = createSignal<Theme>("light");
+	const [isRailCollapsed, setIsRailCollapsed] = createSignal(false);
+	const [isSidebarCollapsed, setIsSidebarCollapsed] = createSignal(false);
 
 	onMount((): void => {
 		setThemeState(getDocumentTheme());
@@ -27,20 +29,37 @@ export const AppShell = (): JSX.Element => {
 		<div class={styles.shell}>
 			<TopBar theme={themeState()} onToggleTheme={toggleTheme} />
 
-			<div class={styles.body}>
+			<div
+				classList={{
+					[styles.body]: true,
+					[styles.bodyRailCollapsed]: isRailCollapsed(),
+					[styles.bodySidebarCollapsed]: isSidebarCollapsed(),
+				}}
+			>
 				{/* Left server rail */}
 				<div class={styles.railColumn}>
-					<LeftRail />
+					<LeftRail collapsed={isRailCollapsed()} />
 				</div>
 
 				{/* Sidebar + main workspace frame */}
 				<div class={styles.workspaceRegion}>
 					<div class={styles.sidebarColumn}>
-						<WorkspaceSidebar />
+						<WorkspaceSidebar
+							collapsed={isSidebarCollapsed()}
+							railCollapsed={isRailCollapsed()}
+							onToggleRailCollapse={(): void => {
+								setIsRailCollapsed((collapsed) => !collapsed);
+							}}
+						/>
 					</div>
 
 					<div class={styles.workspaceMain}>
-						<WorkspaceHome />
+						<WorkspaceHome
+							sidebarCollapsed={isSidebarCollapsed()}
+							onToggleSidebarCollapse={(): void => {
+								setIsSidebarCollapsed((collapsed) => !collapsed);
+							}}
+						/>
 					</div>
 				</div>
 

Frontend/src/components/shell/LeftRail/LeftRail.module.scss

@@ -1,7 +1,6 @@
 .rail {
   --rail-workspace-size: var(--control-size-lg);
   --rail-action-size: var(--control-size-md);
-  --rail-dock-clearance: 8rem;
   position: relative;
   z-index: 3;
   flex: 1;
@@ -10,10 +9,19 @@
   flex-direction: column;
   align-items: center;
   gap: var(--space-3);
-  padding: var(--space-3) var(--space-2) calc(var(--space-3) + var(--rail-dock-clearance));
+  padding: var(--space-3) var(--space-2) calc(var(--space-3) + var(--rail-dock-clearance, 8rem));
   overflow: visible;
 }
 
+.railCollapsed {
+  --rail-workspace-size: calc(var(--control-size-md) + 0.1rem);
+  --rail-action-size: calc(var(--control-size-md) + 0.1rem);
+  justify-content: flex-start;
+  gap: 0;
+  padding-top: var(--space-4);
+  padding-inline: var(--space-1);
+}
+
 .topCluster,
 .bottomCluster {
   width: 100%;
@@ -25,12 +33,22 @@
 
 .bottomCluster {
   margin-top: auto;
+  margin-bottom: var(--rail-bottom-offset, 0rem);
 }
 
 .topCluster {
   gap: var(--space-3);
 }
 
+.railCollapsed .topCluster {
+  gap: var(--space-3);
+}
+
+.railCollapsed .topCluster,
+.railCollapsed .bottomCluster {
+  align-items: center;
+}
+
 .items {
   width: 100%;
   min-height: 0;

Frontend/src/components/shell/LeftRail/LeftRail.tsx

@@ -1,6 +1,6 @@
 // Path: Frontend/src/components/shell/LeftRail/LeftRail.tsx
 
-import { For, type JSX } from "solid-js";
+import { For, Show, type JSX } from "solid-js";
 import { Plus } from "../../../lib/icons";
 import { railItems, type RailItem } from "../data/shell.data";
 import styles from "./LeftRail.module.scss";
@@ -42,29 +42,49 @@ const RailEntry = (props: RailEntryProps): JSX.Element => {
 	);
 };
 
-export const LeftRail = (): JSX.Element => {
+type LeftRailProps = {
+	collapsed: boolean;
+};
+
+export const LeftRail = (props: LeftRailProps): JSX.Element => {
 	const personalItem = railItems.find((item) => item.kind === "personal");
 	const organizationItems = railItems.filter((item) => item.kind === "organization");
 
 	return (
-		<aside class={styles.rail} aria-label="Server rail">
+		<aside
+			classList={{
+				[styles.rail]: true,
+				[styles.railCollapsed]: props.collapsed,
+			}}
+			aria-label="Server rail"
+		>
 			<div class={styles.topCluster}>
-				{personalItem ? <RailEntry item={personalItem} label={personalItem.label} abbreviation="M" personal /> : null}
+				<Show when={!props.collapsed && personalItem}>
+					{(item): JSX.Element => (
+						<RailEntry item={item()} label={item().label} abbreviation={item().abbreviation} personal />
+					)}
+				</Show>
 
-				<div class={styles.sectionDivider} aria-hidden="true" />
+				<Show when={!props.collapsed}>
+					<div class={styles.sectionDivider} aria-hidden="true" />
+				</Show>
 			</div>
 
-			<div class={styles.items}>
+			<Show when={!props.collapsed}>
-				<For each={organizationItems}>
+				<div class={styles.items}>
-					{(item): JSX.Element => <RailEntry item={item} label={item.label} abbreviation={item.abbreviation} />}
+					<For each={organizationItems}>
-				</For>
+						{(item): JSX.Element => <RailEntry item={item} label={item.label} abbreviation={item.abbreviation} />}
-			</div>
+					</For>
+				</div>
+			</Show>
 
-			<div class={styles.bottomCluster}>
+			<Show when={!props.collapsed}>
-				<button type="button" class={styles.addButton} aria-label="Create server" title="Create server">
+				<div class={styles.bottomCluster}>
-					<Plus size={16} strokeWidth={2} />
+					<button type="button" class={styles.addButton} aria-label="Create server" title="Create server">
-				</button>
+						<Plus size={16} strokeWidth={2} />
-			</div>
+					</button>
+				</div>
+			</Show>
 		</aside>
 	);
 };

Frontend/src/components/shell/ProjectSelector/ProjectSelector.module.scss

@@ -5,6 +5,10 @@
   --project-drawer-bottom: calc(var(--sidebar-dock-clearance) + var(--project-drawer-gap));
 }
 
+.rootCompact {
+  justify-items: center;
+}
+
 .trigger {
   width: 100%;
   min-width: 0;
@@ -39,6 +43,29 @@
   box-shadow: var(--shadow-soft);
 }
 
+.triggerCompact {
+  width: var(--control-size-xl);
+  min-height: var(--control-size-xl);
+  grid-template-columns: auto;
+  justify-items: center;
+  gap: 0.15rem;
+  padding: var(--space-2) 0;
+  border-radius: var(--radius-xl);
+}
+
+.triggerCompact .triggerLead {
+  width: var(--control-size-md);
+  height: var(--control-size-md);
+}
+
+.triggerCompact .triggerIcon {
+  transform: rotate(0deg);
+}
+
+.triggerCompact .triggerIconOpen {
+  transform: rotate(180deg);
+}
+
 .triggerLead {
   width: var(--control-size-md);
   height: var(--control-size-md);
@@ -99,6 +126,13 @@
   pointer-events: auto;
 }
 
+.rootCompact .scrim,
+.rootCompact .drawer {
+  left: 0;
+  right: auto;
+  width: min(18rem, calc(100vw - 6rem));
+}
+
 .drawer {
   position: absolute;
   inset: calc(var(--project-drawer-top) + var(--project-drawer-gap)) var(--space-4)

Frontend/src/components/shell/ProjectSelector/ProjectSelector.tsx

@@ -6,6 +6,7 @@ import { activeProject, projectItems } from "../data/shell.data";
 import styles from "./ProjectSelector.module.scss";
 
 type ProjectSelectorProps = {
+	compact?: boolean;
 	isOpen: boolean;
 	onToggle: () => void;
 	onClose: () => void;
@@ -68,7 +69,10 @@ export const ProjectSelector = (props: ProjectSelectorProps): JSX.Element => {
 
 	return (
 		<div
-			class={styles.root}
+			classList={{
+				[styles.root]: true,
+				[styles.rootCompact]: !!props.compact,
+			}}
 			style={{
 				"--project-drawer-top": `${drawerTop()}px`,
 			}}
@@ -79,20 +83,23 @@ export const ProjectSelector = (props: ProjectSelectorProps): JSX.Element => {
 				ref={triggerRef}
 				classList={{
 					[styles.trigger]: true,
+					[styles.triggerCompact]: !!props.compact,
 					[styles.triggerOpen]: props.isOpen,
 				}}
-				aria-label="Open project drawer"
+				aria-label={`Open left workspace sidebar menu for ${selectedProject().name}`}
 				aria-expanded={props.isOpen}
-				title="Open project drawer"
+				title={selectedProject().name}
 				onClick={toggleOpen}
 			>
 				<span class={styles.triggerLead} aria-hidden="true">
 					<Folder size={18} strokeWidth={2} />
 				</span>
-				<span class={styles.triggerCopy}>
+				{!props.compact ? (
-					<span class={styles.eyebrow}>Projects</span>
+					<span class={styles.triggerCopy}>
-					<span class={styles.value}>{selectedProject().name}</span>
+						<span class={styles.eyebrow}>Projects</span>
-				</span>
+						<span class={styles.value}>{selectedProject().name}</span>
+					</span>
+				) : null}
 				<ChevronDown
 					classList={{
 						[styles.triggerIcon]: true,

Frontend/src/components/shell/WorkspaceSidebar/WorkspaceSidebar.module.scss

@@ -1,6 +1,5 @@
 .sidebar {
   --sidebar-nav-item-min-height: var(--control-size-lg);
-  --sidebar-dock-clearance: 8rem;
   position: relative;
   min-width: 0;
   min-height: 0;
@@ -15,13 +14,60 @@
 
 .header {
   display: grid;
+  gap: var(--space-3);
+}
+
+.headerActions {
+  display: grid;
+  grid-template-columns: repeat(4, minmax(0, 1fr));
   gap: var(--space-2);
+  justify-items: stretch;
+}
+
+.headerControls {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr);
+  align-items: start;
 }
 
 .headerDrawerOpen {
   z-index: 4;
 }
 
+.headerActionButton {
+  width: 100%;
+  min-height: var(--control-size-md);
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  border: 1px solid color-mix(in srgb, var(--color-border-strong) 44%, transparent);
+  border-radius: var(--radius-pill);
+  background: color-mix(in srgb, var(--color-surface) 94%, transparent);
+  color: var(--color-text-muted);
+  box-shadow: var(--shadow-soft);
+  transition:
+    background 160ms var(--easing-standard),
+    color 160ms var(--easing-standard),
+    border-color 160ms var(--easing-standard),
+    transform 180ms var(--easing-standard);
+}
+
+.headerActionButton:hover,
+.headerActionButton:focus-visible {
+  background: var(--color-surface-hover);
+  border-color: var(--color-border);
+  color: var(--color-text);
+}
+
+.headerActionButton:hover {
+  transform: translateY(-1px);
+}
+
+.headerCollapseButton {
+  background: color-mix(in srgb, var(--color-accent-soft) 58%, transparent);
+  color: var(--color-accent-strong);
+}
+
 .section {
   display: grid;
   grid-template-rows: auto minmax(0, 1fr);
@@ -45,7 +91,7 @@
   overflow-y: auto;
   overscroll-behavior: contain;
   padding-right: var(--space-1);
-  padding-bottom: calc(var(--space-4) + var(--sidebar-dock-clearance));
+  padding-bottom: calc(var(--space-4) + var(--sidebar-dock-clearance, 8rem));
   margin-right: calc(var(--space-1) * -1);
 }
 
@@ -97,6 +143,50 @@
   color: var(--color-text-muted);
 }
 
+.sidebarCollapsed {
+  gap: var(--space-3);
+  padding: var(--space-3) var(--space-2);
+}
+
+.sidebarCollapsed .headerActions {
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+}
+
+.sidebarCollapsed .headerControls {
+  justify-items: center;
+}
+
+.sidebarCollapsed .header {
+  justify-items: center;
+}
+
+.sidebarCollapsed .navScroller {
+  padding-right: 0;
+  margin-right: 0;
+}
+
+.sidebarCollapsed .navItem {
+  grid-template-columns: auto;
+  justify-content: center;
+  gap: 0;
+  min-height: calc(var(--control-size-lg) - var(--space-1));
+  padding: var(--space-2);
+  border-radius: var(--radius-md);
+}
+
+.sidebarCollapsed .label,
+.sidebarCollapsed .itemMeta {
+  display: none;
+}
+
+.sidebarCollapsed .icon {
+  opacity: 1;
+}
+
+.sidebarCollapsed .section {
+  gap: var(--space-3);
+}
+
 @include respond-down(mobile) {
   .sidebar {
     display: none;

Frontend/src/components/shell/WorkspaceSidebar/WorkspaceSidebar.tsx

@@ -1,30 +1,74 @@
 // Path: Frontend/src/components/shell/WorkspaceSidebar/WorkspaceSidebar.tsx
 
 import { For, Show, createSignal, type JSX } from "solid-js";
+import { ChevronLeft, ChevronRight } from "../../../lib/icons";
 import { ProjectSelector } from "../ProjectSelector/ProjectSelector";
-import { serverSidebarItems } from "../data/shell.data";
+import { serverSidebarItems, workspaceSidebarHeaderActions } from "../data/shell.data";
 import styles from "./WorkspaceSidebar.module.scss";
 
-export const WorkspaceSidebar = (): JSX.Element => {
+type WorkspaceSidebarProps = {
+	collapsed: boolean;
+	railCollapsed: boolean;
+	onToggleRailCollapse: () => void;
+};
+
+export const WorkspaceSidebar = (props: WorkspaceSidebarProps): JSX.Element => {
 	const [isProjectDrawerOpen, setIsProjectDrawerOpen] = createSignal(false);
+	const railToggleLabel = (): string => (props.railCollapsed ? "Expand server rail" : "Collapse server rail");
 
 	return (
-		<aside class={styles.sidebar} aria-label="Server navigation">
+		<aside
+			classList={{
+				[styles.sidebar]: true,
+				[styles.sidebarCollapsed]: props.collapsed,
+			}}
+			aria-label="Left workspace sidebar"
+		>
 			<div
 				classList={{
 					[styles.header]: true,
 					[styles.headerDrawerOpen]: isProjectDrawerOpen(),
 				}}
 			>
-				<ProjectSelector
+				<div class={styles.headerActions}>
-					isOpen={isProjectDrawerOpen()}
+					<button
-					onToggle={(): void => {
+						type="button"
-						setIsProjectDrawerOpen(true);
+						classList={{
-					}}
+							[styles.headerActionButton]: true,
-					onClose={(): void => {
+							[styles.headerCollapseButton]: true,
-						setIsProjectDrawerOpen(false);
+						}}
-					}}
+						aria-label={railToggleLabel()}
-				/>
+						title={railToggleLabel()}
+						onClick={props.onToggleRailCollapse}
+					>
+						{props.railCollapsed ? <ChevronRight size={16} strokeWidth={2} /> : <ChevronLeft size={16} strokeWidth={2} />}
+					</button>
+
+					<For each={workspaceSidebarHeaderActions}>
+						{(action): JSX.Element => {
+							const Icon = action.icon;
+
+							return (
+								<button type="button" class={styles.headerActionButton} aria-label={action.label} title={action.label}>
+									<Icon size={16} strokeWidth={2} />
+								</button>
+							);
+						}}
+					</For>
+				</div>
+
+				<div class={styles.headerControls}>
+					<ProjectSelector
+						compact={props.collapsed}
+						isOpen={isProjectDrawerOpen()}
+						onToggle={(): void => {
+							setIsProjectDrawerOpen(true);
+						}}
+						onClose={(): void => {
+							setIsProjectDrawerOpen(false);
+						}}
+					/>
+				</div>
 			</div>
 
 			<div
@@ -33,7 +77,9 @@ export const WorkspaceSidebar = (): JSX.Element => {
 					[styles.sectionHidden]: isProjectDrawerOpen(),
 				}}
 			>
-				<span class={styles.sectionLabel}>Navigation</span>
+				<Show when={!props.collapsed}>
+					<span class={styles.sectionLabel}>Navigation</span>
+				</Show>
 				<div class={styles.navScroller}>
 					<ul class={styles.navList} role="list">
 						<For each={serverSidebarItems}>
@@ -48,6 +94,8 @@ export const WorkspaceSidebar = (): JSX.Element => {
 												[styles.navItem]: true,
 												[styles.navItemActive]: !!item.active,
 											}}
+											aria-label={item.label}
+											title={item.label}
 										>
 											<Icon class={styles.icon} size={18} strokeWidth={2} />
 											<span class={styles.label}>{item.label}</span>

Frontend/src/components/shell/data/shell.data.ts

@@ -9,6 +9,7 @@ import {
 	Keyboard,
 	LayoutGrid,
 	LogOut,
+	Plus,
 	Repeat,
 	Search,
 	Settings,
@@ -81,6 +82,12 @@ export type SidebarItem = {
 	meta?: string;
 };
 
+export type SidebarHeaderAction = {
+	id: string;
+	label: string;
+	icon: ShellIcon;
+};
+
 export type TopBarAction = {
 	id: string;
 	label: string;
@@ -172,6 +179,12 @@ export const serverSidebarItems: readonly SidebarItem[] = [
 	{ id: "settings", label: "Settings", icon: Settings },
 ] as const;
 
+export const workspaceSidebarHeaderActions: readonly SidebarHeaderAction[] = [
+	{ id: "workspace-settings", label: "Workspace settings", icon: Settings },
+	{ id: "search-workspace", label: "Search workspace", icon: Search },
+	{ id: "create-board", label: "Create board", icon: Plus },
+] as const;
+
 export const topBarActions: readonly TopBarAction[] = [
 	{ id: "search", label: "Search", icon: Search },
 ] as const;

Frontend/src/components/workspace-home/WorkspaceHome/WorkspaceHome.module.scss

@@ -9,6 +9,71 @@
   padding: var(--space-5) var(--space-6);
 }
 
+.workspaceTopBar {
+  width: 100%;
+  display: grid;
+  grid-template-columns: auto minmax(0, 1fr) auto;
+  align-items: center;
+	gap: var(--space-2);
+	min-height: calc(var(--control-size-md) - var(--space-3));
+	padding: 0;
+}
+
+.workspaceTopBarStart,
+.workspaceTopBarEnd {
+	min-width: calc(var(--control-size-md) - 0.5rem);
+  display: inline-flex;
+  align-items: center;
+}
+
+.workspaceTopBarEnd {
+  justify-content: flex-end;
+}
+
+.workspaceTopBarCenter {
+  min-width: 0;
+  display: flex;
+  justify-content: center;
+}
+
+.workspaceBreadcrumb {
+	@include text-caption;
+  min-width: 0;
+  color: var(--color-text-muted);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.workspaceCollapseButton {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+	width: calc(var(--control-size-md) - 0.5rem);
+	height: calc(var(--control-size-md) - 0.5rem);
+  border: 1px solid color-mix(in srgb, var(--color-border-strong) 44%, transparent);
+  border-radius: var(--radius-pill);
+  background: color-mix(in srgb, var(--color-surface) 94%, transparent);
+  color: var(--color-text-muted);
+  box-shadow: var(--shadow-soft);
+  transition:
+    background 160ms var(--easing-standard),
+    color 160ms var(--easing-standard),
+    border-color 160ms var(--easing-standard),
+    transform 180ms var(--easing-standard);
+}
+
+.workspaceCollapseButton:hover,
+.workspaceCollapseButton:focus-visible {
+  background: var(--color-surface-hover);
+  border-color: var(--color-border);
+  color: var(--color-text);
+}
+
+.workspaceCollapseButton:hover {
+  transform: translateY(-1px);
+}
+
 .hero {
   display: grid;
   gap: var(--space-3);
@@ -76,4 +141,21 @@
     gap: var(--space-4);
     padding: var(--space-4);
   }
+
+  .workspaceTopBar {
+    grid-template-columns: auto minmax(0, 1fr);
+  }
+
+  .workspaceTopBarEnd {
+    display: none;
+  }
+
+  .workspaceTopBarCenter {
+    justify-content: flex-start;
+  }
+
+	.workspaceCollapseButton {
+		width: calc(var(--control-size-md) - 0.5rem);
+		height: calc(var(--control-size-md) - 0.5rem);
+	}
 }

Frontend/src/components/workspace-home/WorkspaceHome/WorkspaceHome.tsx

@@ -1,7 +1,8 @@
 // Path: Frontend/src/components/workspace-home/WorkspaceHome/WorkspaceHome.tsx
 
 import { For, type JSX } from "solid-js";
-import { activeServer } from "../../shell/data/shell.data";
+import { ChevronLeft, ChevronRight } from "../../../lib/icons";
+import { activeProject, activeServer } from "../../shell/data/shell.data";
 import styles from "./WorkspaceHome.module.scss";
 
 type ShellCheckpointCard = {
@@ -28,9 +29,37 @@ const shellCheckpointCards: readonly ShellCheckpointCard[] = [
 	},
 ];
 
-export const WorkspaceHome = (): JSX.Element => {
+type WorkspaceHomeProps = {
+	sidebarCollapsed: boolean;
+	onToggleSidebarCollapse: () => void;
+};
+
+export const WorkspaceHome = (props: WorkspaceHomeProps): JSX.Element => {
+	const sidebarToggleLabel = (): string => (props.sidebarCollapsed ? "Expand left workspace sidebar" : "Collapse left workspace sidebar");
+	const breadcrumb = (): string => `${activeServer.name} / ${activeProject.name} / Home`;
+
 	return (
 		<main class={styles.viewport}>
+			<div class={styles.workspaceTopBar}>
+				<div class={styles.workspaceTopBarStart}>
+					<button
+						type="button"
+						class={styles.workspaceCollapseButton}
+						aria-label={sidebarToggleLabel()}
+						title={sidebarToggleLabel()}
+						onClick={props.onToggleSidebarCollapse}
+					>
+						{props.sidebarCollapsed ? <ChevronRight size={16} strokeWidth={2} /> : <ChevronLeft size={16} strokeWidth={2} />}
+					</button>
+				</div>
+
+				<div class={styles.workspaceTopBarCenter}>
+					<span class={styles.workspaceBreadcrumb}>{breadcrumb()}</span>
+				</div>
+
+				<div class={styles.workspaceTopBarEnd} aria-hidden="true" />
+			</div>
+
 			<section class={styles.hero}>
 				<span class={styles.eyebrow}>Server home</span>
 				<h1 class={styles.title}>{activeServer.name} is ready for its first real shell.</h1>

Frontend/src/lib/icons/index.ts

@@ -3,6 +3,8 @@
 export { default as Bell } from "lucide-solid/icons/bell";
 export { default as CircleHelp } from "lucide-solid/icons/circle-help";
 export { default as ChevronDown } from "lucide-solid/icons/chevron-down";
+export { default as ChevronLeft } from "lucide-solid/icons/chevron-left";
+export { default as ChevronRight } from "lucide-solid/icons/chevron-right";
 export { default as Folder } from "lucide-solid/icons/folder";
 export { default as Home } from "lucide-solid/icons/house";
 export { default as Keyboard } from "lucide-solid/icons/keyboard";
@@ -12,7 +14,6 @@ export { default as Moon } from "lucide-solid/icons/moon";
 export { default as Plus } from "lucide-solid/icons/plus";
 export { default as Repeat } from "lucide-solid/icons/repeat";
 export { default as Search } from "lucide-solid/icons/search";
-export { default as Server } from "lucide-solid/icons/server";
 export { default as Settings } from "lucide-solid/icons/settings";
 export { default as Shield } from "lucide-solid/icons/shield";
 export { default as Sun } from "lucide-solid/icons/sun";