Update frontend for presets, tabs, and help

Align frontend with new preset ID usage and shortened driver fields, improve tab/preset interactions, and refine help and editor UI.

src/static/tabs.js

@@ -20,7 +20,20 @@ async function loadTabs() {
         const data = await response.json();
         
         // Get current tab from cookie first, then from server response
-        currentTabId = getCurrentTabFromCookie() || data.current_tab_id;
+        const cookieTabId = getCurrentTabFromCookie();
+        const serverCurrent = data.current_tab_id;
+        const tabs = data.tabs || {};
+        const tabIds = Object.keys(tabs);
+
+        let candidateId = cookieTabId || serverCurrent || null;
+        // If the candidate doesn't exist anymore (e.g. after DB reset), fall back to first tab.
+        if (candidateId && !tabIds.includes(String(candidateId))) {
+            candidateId = tabIds.length > 0 ? tabIds[0] : null;
+            // Clear stale cookie
+            document.cookie = 'current_tab=; path=/; max-age=0';
+        }
+
+        currentTabId = candidateId;
         renderTabsList(data.tabs, data.tab_order, currentTabId);
         
         // Load current tab content if available