clean exemple/navigation to a minimal working example

- index.html: fix title and typo, add missing #error div
- config.json: replace project-specific keys with generic api_url
- core/menu.js: remove Voltalis mock data, leave commented usage pattern
- dashboard.js: move logic to init(), Custom Element is a plain shell
- dashboard.css: add real styles, remove placeholder comment
- manifest.json: drop unused version field
- config.yml: fix web/vendor comment → sources/vendor

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

exemple/navigation/sources/pages/dashboard/dashboard.css

@@ -1,2 +1,15 @@
-/* Styles scoped to the dashboard page.
-   Applied when the route is active, removed on navigation. */
+.dashboard {
+  padding: 8px;
+}
+
+.dashboard h2 {
+  font-size: 20px;
+  font-weight: 600;
+  color: #cdd6f4;
+  margin-bottom: 8px;
+}
+
+.dashboard p {
+  color: #6c7086;
+  font-size: 14px;
+}

exemple/navigation/sources/pages/dashboard/dashboard.js

@@ -1,2 +1,10 @@
+customElements.define('dashboard-page', class extends HTMLElement {})
+
 export function init(main) {
+  main.querySelector('dashboard-page').innerHTML = `
+    <div class="dashboard">
+      <h2>Dashboard</h2>
+      <p>Page d'exemple chargée via le routeur Syn.</p>
+    </div>
+  `
 }

exemple/navigation/sources/pages/dashboard/index.html

@@ -1 +1 @@
-Cecie est la premiere page
+<dashboard-page></dashboard-page>

exemple/navigation/sources/pages/dashboard/manifest.json

@@ -1,6 +1,5 @@
 {
-  "route":   "dashboard",
-  "label":   "Dashboard",
-  "icon":    "dashboard",
-  "version": "0.1.0"
+  "route": "dashboard",
+  "label": "Dashboard",
+  "icon":  "dashboard"
 }