visual fixes

api/src/lib/store.js

@@ -31,6 +31,7 @@ export const DEFAULT_UNIT_DEFINITIONS = [
   { symbol: "V", label: "Volt", isSystem: true },
   { symbol: "A", label: "Ampere", isSystem: true },
   { symbol: "Pa", label: "Pascal", isSystem: true },
+  { symbol: "bool", label: "Digital / Bool", isSystem: true },
 ];
 
 function safeParse(jsonValue) {
@@ -267,6 +268,7 @@ export async function getPreferences(redis, userId) {
     theme: "system",
     csvDelimiter: ";",
     sidebarPinned: true,
+    trendLineWidth: 1.8,
   };
 }
 
@@ -278,6 +280,7 @@ export async function savePreferences(redis, userId, preferences) {
     theme: preferences.theme || current.theme || "system",
     csvDelimiter: preferences.csvDelimiter || current.csvDelimiter || ";",
     sidebarPinned: typeof preferences.sidebarPinned === "boolean" ? preferences.sidebarPinned : current.sidebarPinned,
+    trendLineWidth: Number.isFinite(Number(preferences.trendLineWidth)) ? Number(preferences.trendLineWidth) : Number(current.trendLineWidth || 1.8),
     updatedAt: new Date().toISOString(),
   };
   await redis.set(`preferences:${userId}`, JSON.stringify(payload));