fix: WORKSPSACES section + remaining emoji icons replaced

- base.html: séparateur entre version et Log out, _local_workspaces_for_user
- board.py: _local_workspaces_for_user helper, app_version, fix emoji icons
- dashboard.py: _local_workspaces_for_user helper
- library.html: 📚📁📄🕒⭐👥🌐🔒📦 → SVG + icon map
- workspaces.html: 📁🔍🗑📝 → SVG
- local_workspace.html: page_icon, empty states, icon functions → SVG
- settings.html: 👤🔔 → SVG nav icons
- _icons.html: +'bell' icon
- CSS: .nav-icon-inline, .empty-state-icon
- 143 tests passent

app/templates/_icons.html

@@ -46,6 +46,8 @@
 <svg width="{{s}}" height="{{s}}" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"/><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"/></svg>
 {%- elif name == 'plus' -%}
 <svg width="{{s}}" height="{{s}}" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="12" y1="5" x2="12" y2="19"/><line x1="5" y1="12" x2="19" y2="12"/></svg>
+{%- elif name == 'bell' -%}
+<svg width="{{s}}" height="{{s}}" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M18 8A6 6 0 0 0 6 8c0 7-3 9-3 9h18s-3-2-3-9"/><path d="M13.73 21a2 2 0 0 1-3.46 0"/></svg>
 {%- elif name == 'chevron-down' -%}
 <svg width="{{s}}" height="{{s}}" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="6 9 12 15 18 9"/></svg>
 {%- elif name == 'inbox' -%}