fix: Home button pointe vers workspace par défaut au lieu de /workspaces

- Si local_workspaces existe: redirige vers /local-workspace?ws=<premier id>
- Sinon (fallback): redirige vers /workspaces
- 143 tests passent

app/templates/base.html

@@ -198,7 +198,7 @@
 
     <!-- Navigation icons row -->
     <div class="sidebar-nav-row">
-      <a href="/workspaces" class="nav-icon-btn home-btn" :class="{ active: currentView === 'home' }" title="Home">
+      <a href="{% if local_workspaces and local_workspaces|length > 0 %}/local-workspace?ws={{ local_workspaces[0].id }}{% else %}/workspaces{% endif %}" class="nav-icon-btn home-btn" :class="{ active: currentView === 'home' }" title="Home">
         <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M3 9l9-7 9 7v11a2 2 0 01-2 2H5a2 2 0 01-2-2z"/></svg>
         Home
       </a>