feat: unified rail shell, robust live sync, task board performance

Shell:
- One shared NexusLayout for ALL routes (dashboard + pages): compact 68px
  icon rail with hover-expand overlay, replaces both old sidebars + topbars
- Single flat nav source (railNav) — same menu everywhere incl. Settings
- Removed dead shell components (AppSidebar, AppHeader, Topbar, NavGroup,
  NavItem, ModuleView) and dead nav routes; App.vue is now just RouterView

Live updates:
- Fix SSE loop in DashboardController: PeriodicTimer.WaitForNextTickAsync and
  ChannelReader.ReadAsync were re-invoked while pending — every published
  update threw InvalidOperationException and killed ALL live streams
- liveSync store: treat graceful stream close as disconnect (was stuck
  connected=true with polling stopped -> page frozen until manual reload),
  fast first retry, heartbeat watchdog (65s), reconnect on online/visibility
- One app-wide SSE connection owned by the layout instead of per-view
  connect/disconnect churn; removed duplicate live-sync.ts store

Performance:
- Board endpoint: drop nested childTasks duplication (counts stay) — payload
  104KB -> 65KB; SSE snapshots shrink equally
- nginx: gzip for JSON/JS/CSS (board 18KB, bundle 95KB over the wire);
  text/event-stream excluded to keep SSE unbuffered

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/components/layout/Sidebar.vue

@@ -1,139 +1,180 @@
 <script setup lang="ts">
+/**
+ * Sidebar — kompakte Icon-Rail (V2-Shell, alle Seiten)
+ *
+ * Collapsed 68px, expandiert bei Hover auf 232px als Overlay
+ * (kein Layout-Shift im Content). Ersetzt Sidebar + Topbar.
+ * Mobile: als Drawer über mobileOpen/close.
+ */
 import { computed } from 'vue'
-import { useRouter } from 'vue-router'
+import { useRoute, useRouter } from 'vue-router'
 import { useAuthStore } from '../../stores/auth'
-import { useAgentStore } from '../../stores/agents'
-import { useTaskStore } from '../../stores/tasks'
-import { navigation, icons } from '../../composables/icons'
-import type { NavGroupDef } from '../../composables/icons'
+import { useNotificationStore } from '../../stores/notifications'
+import { useLiveSyncStore } from '../../stores/liveSync'
+import { railNav, railFooterNav, svg } from '../../composables/icons'
+import { initials } from '../../utils/format'
 
 defineProps<{
   mobileOpen?: boolean
 }>()
 
-defineEmits<{
+const emit = defineEmits<{
   close: []
 }>()
-import NavGroup from './NavGroup.vue'
-import { initials } from '../../utils/format'
 
 const auth = useAuthStore()
+const route = useRoute()
 const router = useRouter()
-const agentStore = useAgentStore()
-const taskStore = useTaskStore()
+const notificationStore = useNotificationStore()
+const liveSync = useLiveSyncStore()
 
 const ownerInitials = computed(() =>
   auth.user?.displayName ? initials(auth.user.displayName) : 'OW'
 )
 
-function logout() {
-  auth.logout()
-  router.replace('/login')
+function isActive(itemRoute?: string): boolean {
+  if (!itemRoute) return false
+  if (route.path === itemRoute) return true
+  // Detailrouten (/tasks/:id, /agents/:id) markieren den Hauptpunkt
+  return route.path.startsWith(itemRoute + '/')
 }
 
-/**
- * Dynamische Nav-Item-Counts aus den Stores.
- * Überschreibt die hartcodierten `count`-Werte im navigation-Array.
- */
-const dynamicNavigation = computed<NavGroupDef[]>(() => {
-  // Deep-clone: Jede Gruppe und jedes Item neu erstellen
-  return navigation.map(group => ({
-    ...group,
-    items: group.items.map(item => {
-      let dynamicCount: string | undefined
+function navigate(itemRoute?: string) {
+  if (!itemRoute) return
+  emit('close')
+  router.push(itemRoute)
+}
 
-      switch (item.label) {
-        case 'Agenten':
-        case 'Hosts · OpenClaw':
-          dynamicCount = String(agentStore.agentList.length)
-          break
-        case 'Task Board':
-          dynamicCount = String(taskStore.taskList.length)
-          break
-        case 'Kosten & Tokens':
-          dynamicCount = agentStore.todayCost
-          break
-        case 'Docs & .md':
-          dynamicCount = '0'
-          break
-        case 'Incidents':
-          dynamicCount = '0'
-          break
-      }
+async function logout() {
+  await auth.logout()
+  await router.replace('/login')
+}
 
-      return {
-        ...item,
-        count: dynamicCount ?? item.count,
-      }
-    }),
-  }))
+const statusLabel = computed(() => {
+  if (liveSync.connected) return 'Live'
+  if (liveSync.connecting) return 'Verbinde…'
+  return 'Polling'
 })
 </script>
 
 <template>
-  <aside :class="['sidebar', { open: mobileOpen }]">
-    <button class="sidebar-close" @click="$emit('close')" v-html="icons.chevron_left || ''"></button>
+  <aside :class="['rail', { open: mobileOpen }]">
     <!-- Brand -->
-    <div class="side-top">
-      <div class="brand-mark" v-html="icons.command || ''"></div>
-      <div>
-        <div class="brand-name">NEXUS</div>
-        <div class="brand-sub">Mission Control</div>
-      </div>
-    </div>
+    <button class="rail-brand" @click="navigate('/dashboard')">
+      <span class="brand-mark" v-html="svg('command')"></span>
+      <span class="rail-label brand-label">NEXUS</span>
+    </button>
 
     <!-- Navigation -->
-    <nav class="nav">
-      <NavGroup
-        v-for="(group, idx) in dynamicNavigation"
-        :key="idx"
-        :label="group.group"
-        :items="group.items"
-      />
+    <nav class="rail-nav v2-scroll">
+      <button
+        v-for="item in railNav"
+        :key="item.route"
+        :class="['rail-item', { active: isActive(item.route) }]"
+        :title="item.label"
+        @click="navigate(item.route)"
+      >
+        <span class="rail-icon" v-html="svg(item.icon)"></span>
+        <span
+          v-if="item.route === '/notifications' && notificationStore.unreadCount > 0"
+          class="rail-dot"
+        ></span>
+        <span class="rail-label">{{ item.label }}</span>
+        <span
+          v-if="item.route === '/notifications' && notificationStore.unreadCount > 0"
+          class="rail-count"
+        >{{ notificationStore.unreadCount }}</span>
+      </button>
     </nav>
 
     <!-- Footer -->
-    <div class="side-foot">
-      <div class="avatar">{{ ownerInitials }}</div>
-      <div class="owner-info">
-        <div class="owner-name">{{ auth.user?.displayName ?? 'Owner' }}</div>
-        <div class="owner-role">{{ auth.user?.role ?? 'Owner' }}</div>
+    <div class="rail-foot">
+      <div class="rail-item static" :title="statusLabel">
+        <span class="rail-icon">
+          <span :class="['status-dot', liveSync.connected ? 'on' : 'off']"></span>
+        </span>
+        <span class="rail-label dim">{{ statusLabel }}</span>
+      </div>
+
+      <button
+        v-for="item in railFooterNav"
+        :key="item.route"
+        :class="['rail-item', { active: isActive(item.route) }]"
+        :title="item.label"
+        @click="navigate(item.route)"
+      >
+        <span class="rail-icon" v-html="svg(item.icon)"></span>
+        <span class="rail-label">{{ item.label }}</span>
+      </button>
+
+      <div class="rail-owner">
+        <span class="avatar">{{ ownerInitials }}</span>
+        <span class="rail-label owner-label">
+          <span class="owner-name">{{ auth.user?.displayName ?? 'Owner' }}</span>
+          <span class="owner-role">{{ auth.user?.role ?? 'Owner' }}</span>
+        </span>
+        <button class="logout-btn rail-label" title="Abmelden" @click="logout" v-html="svg('logout')"></button>
       </div>
     </div>
   </aside>
 </template>
 
 <style scoped>
-.sidebar {
-  width: 248px;
-  flex: 0 0 248px;
-  height: 100vh;
+.rail {
+  position: absolute;
+  inset: 0 auto 0 0;
+  width: 68px;
   display: flex;
   flex-direction: column;
-  background: linear-gradient(180deg, rgba(14,12,32,.92), rgba(8,6,20,.92));
+  background: linear-gradient(180deg, rgba(14, 12, 32, 0.92), rgba(8, 6, 20, 0.92));
   border-right: 1px solid var(--line);
   backdrop-filter: blur(14px);
-  padding: 0;
-  position: relative;
-  z-index: 2;
+  overflow: hidden;
+  transition: width .18s ease, box-shadow .18s ease;
+  z-index: 100;
 }
 
-.side-top {
+.rail:hover {
+  width: 232px;
+  box-shadow: 24px 0 60px -30px rgba(0, 0, 0, .8);
+}
+
+/* Labels: unsichtbar bis die Rail expandiert */
+.rail-label {
+  opacity: 0;
+  white-space: nowrap;
+  transition: opacity .14s ease .04s;
+  font-size: 13px;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.rail:hover .rail-label,
+.rail.open .rail-label {
+  opacity: 1;
+}
+
+/* ── Brand ── */
+.rail-brand {
   display: flex;
   align-items: center;
-  gap: 11px;
-  padding: 18px 18px 16px;
+  gap: 13px;
+  padding: 15px;
+  border: none;
+  background: transparent;
+  cursor: pointer;
 }
 
 .brand-mark {
   width: 38px;
   height: 38px;
+  flex: 0 0 38px;
   border-radius: 11px;
   display: grid;
   place-items: center;
   background: var(--grad);
   box-shadow: var(--glow-purple);
-  flex: 0 0 auto;
 }
 
 .brand-mark :deep(svg) {
@@ -142,108 +183,154 @@ const dynamicNavigation = computed<NavGroupDef[]>(() => {
   color: #fff;
 }
 
-.brand-name {
+.brand-label {
   font-family: 'Space Grotesk', sans-serif;
   font-weight: 700;
-  font-size: 17px;
+  font-size: 16px;
   letter-spacing: .14em;
-  line-height: 1;
+  color: var(--tx);
 }
 
-.brand-sub {
-  font-size: 10.5px;
-  color: var(--tx-3);
-  letter-spacing: .05em;
-  margin-top: 3px;
-}
-
-.nav {
+/* ── Nav ── */
+.rail-nav {
   flex: 1;
-  overflow-y: auto;
-  padding: 6px 12px 12px;
   display: flex;
   flex-direction: column;
-  gap: 2px;
+  gap: 3px;
+  padding: 6px 12px;
+  overflow-y: auto;
+  overflow-x: hidden;
 }
 
-.side-foot {
-  padding: 12px;
-  border-top: 1px solid var(--line);
+.rail-item {
+  position: relative;
   display: flex;
   align-items: center;
-  gap: 10px;
+  gap: 13px;
+  height: 42px;
+  padding: 0 13px;
+  flex: 0 0 auto;
+  border: none;
+  border-radius: 11px;
+  background: transparent;
+  color: var(--tx-2);
+  font-family: 'Manrope', sans-serif;
+  font-weight: 500;
+  text-align: left;
   cursor: pointer;
-  transition: background .15s;
+  transition: background .15s, color .15s;
 }
 
-.side-foot:hover {
-  background: rgba(124,108,255,.06);
+.rail-item:not(.static):hover {
+  background: rgba(124, 108, 255, .08);
+  color: var(--tx);
 }
 
-.sidebar-close {
-  display: none;
+.rail-item.active {
+  color: #fff;
+  background: linear-gradient(90deg, rgba(124, 108, 255, .22), rgba(124, 108, 255, .04));
+  box-shadow: inset 0 0 0 1px rgba(124, 108, 255, .25);
 }
 
-@media (max-width: 767px) {
-  .sidebar {
-    position: fixed;
-    left: 0;
-    top: 0;
-    z-index: 100;
-    height: 100vh;
-    width: 280px;
-    transform: translateX(-100%);
-    transition: transform 0.25s ease;
-  }
+.rail-item.static {
+  cursor: default;
+}
 
-  .sidebar.open {
-    transform: translateX(0);
-  }
+.rail-icon {
+  width: 18px;
+  height: 18px;
+  flex: 0 0 18px;
+  display: grid;
+  place-items: center;
+  opacity: .9;
+}
 
-  .sidebar-close {
-    display: flex;
-    align-items: center;
-    justify-content: center;
-    position: absolute;
-    top: 18px;
-    right: 12px;
-    width: 30px;
-    height: 30px;
-    border-radius: 8px;
-    border: none;
-    background: transparent;
-    color: var(--tx-2);
-    cursor: pointer;
-    z-index: 1;
-  }
+.rail-icon :deep(svg) {
+  width: 18px;
+  height: 18px;
+}
 
-  .sidebar-close:hover {
-    background: rgba(124,108,255,.1);
-    color: var(--tx);
-  }
+.rail-item .rail-label {
+  flex: 1;
+}
 
-  .sidebar-close :deep(svg) {
-    width: 18px;
-    height: 18px;
-  }
+/* Ungelesen-Punkt am Icon (collapsed sichtbar) */
+.rail-dot {
+  position: absolute;
+  left: 24px;
+  top: 9px;
+  width: 7px;
+  height: 7px;
+  border-radius: 50%;
+  background: var(--st-block);
+  box-shadow: 0 0 8px rgba(251, 113, 133, .8);
+}
+
+.rail-count {
+  font-family: 'JetBrains Mono', monospace;
+  font-size: 10.5px;
+  font-weight: 600;
+  padding: 1px 8px;
+  border-radius: 20px;
+  background: rgba(251, 113, 133, .16);
+  border: 1px solid rgba(251, 113, 133, .35);
+  color: var(--st-block);
+}
+
+/* ── Footer ── */
+.rail-foot {
+  display: flex;
+  flex-direction: column;
+  gap: 3px;
+  padding: 6px 12px 10px;
+  border-top: 1px solid var(--line);
+}
+
+.status-dot {
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+}
+
+.status-dot.on {
+  background: var(--st-work);
+  animation: pulse-work 1.8s infinite;
+}
+
+.status-dot.off {
+  background: var(--st-idle);
+}
+
+.rail-label.dim {
+  color: var(--tx-3);
+  font-size: 12px;
+}
+
+.rail-owner {
+  display: flex;
+  align-items: center;
+  gap: 13px;
+  padding: 7px 5px 2px;
 }
 
 .avatar {
   width: 34px;
   height: 34px;
+  flex: 0 0 34px;
   border-radius: 10px;
   background: var(--grad-soft);
   border: 1px solid var(--line-2);
   display: grid;
   place-items: center;
   font-weight: 700;
-  font-size: 13px;
+  font-size: 12px;
   color: var(--tx);
-  flex-shrink: 0;
 }
 
-.owner-info {
-  min-width: 0;
+.owner-label {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
 }
 
 .owner-name {
@@ -258,7 +345,41 @@ const dynamicNavigation = computed<NavGroupDef[]>(() => {
 .owner-role {
   font-size: 10px;
   color: var(--tx-3);
-  margin-top: 1px;
   text-transform: capitalize;
 }
+
+.logout-btn {
+  border: none;
+  background: transparent;
+  color: var(--tx-3);
+  cursor: pointer;
+  padding: 6px;
+  border-radius: 8px;
+  display: grid;
+  place-items: center;
+}
+
+.logout-btn:hover {
+  color: var(--st-block);
+  background: rgba(251, 113, 133, .1);
+}
+
+.logout-btn :deep(svg) {
+  width: 16px;
+  height: 16px;
+}
+
+/* ── Mobile: Drawer ── */
+@media (max-width: 767px) {
+  .rail {
+    position: fixed;
+    width: 232px;
+    transform: translateX(-100%);
+    transition: transform .22s ease;
+  }
+
+  .rail.open {
+    transform: translateX(0);
+  }
+}
 </style>