feat: refonte UX du dashboard (coquille, tri/filtre/pagination, ⌘K, toasts)

Refonte front (packages/web) : coquille applicative partagée (sidebar desktop +
barre d'onglets mobile + PageHeader, langue/push/logout centralisés) pilotée par
route.meta.layout ; design system (BaseButton/BaseBadge/SegmentedControl/EmptyState/
SkeletonRow, anneau de focus, icônes @lucide/vue) ; tri/filtre/recherche/pagination
côté client via useListControls (+ synchro URL) sur sessions/worktrees/groupes ;
section « À traiter », palette de commandes ⌘K, toasts. Aucune modif serveur/protocole/DB.

packages/web/src/components/layout/NavItem.vue

@@ -0,0 +1,50 @@
+<template>
+  <RouterLink
+    :to="to"
+    :aria-current="active ? 'page' : undefined"
+    :class="orientation === 'col' ? colClass : rowClass"
+  >
+    <span class="relative">
+      <component :is="icon" :size="orientation === 'col' ? 20 : 18" :stroke-width="1.75" />
+      <span
+        v-if="badge"
+        class="absolute -right-1.5 -top-1.5 flex h-3.5 min-w-3.5 items-center justify-center rounded-full bg-amber-500 px-1 text-[9px] font-semibold text-amber-950"
+      >
+        {{ badge }}
+      </span>
+    </span>
+    <span :class="orientation === 'col' ? 'text-[10px]' : 'flex-1'">{{ label }}</span>
+    <span
+      v-if="badge && orientation === 'row'"
+      class="rounded-full bg-amber-500/20 px-1.5 text-[11px] font-semibold text-amber-300"
+    >
+      {{ badge }}
+    </span>
+  </RouterLink>
+</template>
+
+<script setup lang="ts">
+import { computed, type Component } from 'vue';
+import type { RouteLocationRaw } from 'vue-router';
+
+const props = withDefaults(
+  defineProps<{
+    to: RouteLocationRaw;
+    icon: Component;
+    label: string;
+    badge?: number;
+    active?: boolean;
+    orientation?: 'row' | 'col';
+  }>(),
+  { orientation: 'row' },
+);
+
+const rowClass = computed(() => [
+  'flex items-center gap-2.5 rounded-lg px-3 py-2 text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-emerald-500/70',
+  props.active ? 'bg-zinc-800 text-zinc-100' : 'text-zinc-400 hover:bg-zinc-800/50 hover:text-zinc-200',
+]);
+const colClass = computed(() => [
+  'flex flex-1 flex-col items-center gap-0.5 py-2 transition-colors focus-visible:outline-none',
+  props.active ? 'text-emerald-400' : 'text-zinc-500 hover:text-zinc-300',
+]);
+</script>