Made sidebar item collection extendable via interface. Refactored settings to system

Moonlight.Frontend/UI/Admin/Views/Sys/Index.razor

@@ -0,0 +1,45 @@
+@page "/admin/system"
+@using LucideBlazor
+@using ShadcnBlazor.Buttons
+@using ShadcnBlazor.Cards
+@using ShadcnBlazor.Inputs
+@using ShadcnBlazor.Tab
+@using ShadcnBlazor.Labels
+
+<Tabs DefaultValue="customization">
+    <TabsList ClassName="inline-flex w-full lg:w-fit justify-start overflow-x-auto overflow-y-hidden">
+        <TabsTrigger Value="customization">
+            <PaintRollerIcon />
+            Customization
+        </TabsTrigger>
+        <TabsTrigger Value="api">
+            <KeyIcon />
+            API & API Keys
+        </TabsTrigger>
+        <TabsTrigger Value="diagnose">
+            <HeartPulseIcon />
+            Diagnose
+        </TabsTrigger>
+    </TabsList>
+    <TabsContent Value="customization">
+        <Card ClassName="mt-5">
+            <CardContent>
+                <div class="grid grid-cols-1 lg:grid-cols-3 gap-5">
+                    <div class="col-span-1 grid gap-3">
+                        <Label for="instance-name">Instance Name</Label>
+                        <InputField id="instance-name" />
+                    </div>
+                </div>
+            </CardContent>
+            <CardFooter ClassName="justify-end">
+                <Button>
+                    <SaveIcon />
+                    Save changes
+                </Button>
+            </CardFooter>
+        </Card>
+    </TabsContent>
+    <TabsContent Value="diagnose">
+        <Diagnose />
+    </TabsContent>
+</Tabs>