ui(icons): replace colored emoji with modern single-color line icons (lucide-vue-next)

Add lucide-vue-next (stroke-based, single-color, currentColor) and swap emoji icons
across nav + all main views: Settings/LogOut (App), BarChart3/Users/Plus (Analytics),
LayoutDashboard (MyBoard), Sparkles/Users/Pencil (GroupEdit), Box/ListChecks/Paperclip/
PlusCircle/ArrowLeft (GroupBuilder), Target/ArrowLeft/Search (Chat/Personas/Training),
User/Lock/Globe (Settings), Users/UserPlus/Info (AdminUsers).
- Buttons become inline-flex for icon+text alignment.
- Icons inherit currentColor (single color, modern line style).
- Rebuild dist with lucide.

frontend/dist/assets/users-D5qk1Nmy.js

@@ -0,0 +1,6 @@
+import{k as e}from"./index-C0Orcg9B.js";/**
+ * @license lucide-vue-next v1.0.0 - ISC
+ *
+ * This source code is licensed under the ISC license.
+ * See the LICENSE file in the root directory of this source tree.
+ */const r=e("users",[["path",{d:"M16 21v-2a4 4 0 0 0-4-4H6a4 4 0 0 0-4 4v2",key:"1yyitq"}],["path",{d:"M16 3.128a4 4 0 0 1 0 7.744",key:"16gr8j"}],["path",{d:"M22 21v-2a4 4 0 0 0-3-3.87",key:"kshegd"}],["circle",{cx:"9",cy:"7",r:"4",key:"nufk8"}]]);export{r as U};