feat(v0.11.6): FileBrowser auto-mount sync + UI polish

- Add syncFileBrowserMounts() and generateFileBrowserCompose() to handlers.go
- Call syncFileBrowserMounts() after storage path add (storage init) and remove
- settings.html: red 'Nincs csatolva!' badge → yellow 'Rendszermeghajtón' (badge-warn)
- settings.html: 'Alapértelmezett' button → 'Legyen alapértelmezett' (action clarity)
- storage_init.html: replace disk-usage zone gradient bar with clean progress-bar-task
- style.css: add .badge-warn and .progress-bar-task CSS classes

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

controller/internal/web/templates/style.css

@@ -2090,6 +2090,29 @@ a.stat-card:hover {
 .storage-app-link:hover {
     text-decoration: underline;
 }
+
+/* Badge variants */
+.badge-warn {
+    background: rgba(250, 204, 21, 0.15);
+    color: #facc15;
+}
+
+/* Task progress bar (storage init — not disk usage zone gradient) */
+.progress-bar-task {
+    height: 8px;
+    background: var(--border-color);
+    border-radius: 4px;
+    overflow: hidden;
+    width: 100%;
+}
+
+.progress-bar-task .progress-fill {
+    height: 100%;
+    background: var(--accent-blue);
+    border-radius: 4px;
+    transition: width 0.3s ease;
+}
+
 .storage-path-label-wrap {
     display: flex;
     align-items: center;