refactor(frontend): restructure project layout and update API schema

Relocate frontend source code from `next-app/` to `frontend/` to align with the new project structure. This includes removing the old Next.js boilerplate files and establishing a cleaner workspace.

Additionally, updates the OpenAPI specification to include support for the `immich` widget type and its corresponding configuration schema.

- Move frontend files to `frontend/`
- Delete obsolete `next-app/` directory and its configuration
- Add `immich` widget type to `openapi.yaml`
- Update `FrontendPlan.md` with dashboard refactor and UX direction

frontend/components/ui/command.tsx

@@ -0,0 +1,69 @@
+"use client";
+
+import * as React from "react";
+import { Command as CommandPrimitive } from "cmdk";
+import { Search } from "lucide-react";
+import { cn } from "@/lib/utils";
+
+const Command = React.forwardRef<
+  React.ComponentRef<typeof CommandPrimitive>,
+  React.ComponentPropsWithoutRef<typeof CommandPrimitive>
+>(({ className, ...props }, ref) => (
+  <CommandPrimitive
+    ref={ref}
+    className={cn("flex h-full w-full flex-col overflow-hidden rounded-md bg-popover text-popover-foreground", className)}
+    {...props}
+  />
+));
+Command.displayName = CommandPrimitive.displayName;
+
+const CommandInput = React.forwardRef<
+  React.ComponentRef<typeof CommandPrimitive.Input>,
+  React.ComponentPropsWithoutRef<typeof CommandPrimitive.Input>
+>(({ className, ...props }, ref) => (
+  <div className="flex items-center border-b border-border px-3" cmdk-input-wrapper="">
+    <Search className="mr-2 h-4 w-4 shrink-0 opacity-50" />
+    <CommandPrimitive.Input
+      ref={ref}
+      className={cn("flex h-10 w-full rounded-md bg-transparent py-3 text-sm outline-none placeholder:text-muted-foreground disabled:cursor-not-allowed disabled:opacity-50", className)}
+      {...props}
+    />
+  </div>
+));
+CommandInput.displayName = CommandPrimitive.Input.displayName;
+
+const CommandList = React.forwardRef<
+  React.ComponentRef<typeof CommandPrimitive.List>,
+  React.ComponentPropsWithoutRef<typeof CommandPrimitive.List>
+>(({ className, ...props }, ref) => (
+  <CommandPrimitive.List ref={ref} className={cn("max-h-[300px] overflow-y-auto overflow-x-hidden p-1", className)} {...props} />
+));
+CommandList.displayName = CommandPrimitive.List.displayName;
+
+const CommandItem = React.forwardRef<
+  React.ComponentRef<typeof CommandPrimitive.Item>,
+  React.ComponentPropsWithoutRef<typeof CommandPrimitive.Item>
+>(({ className, ...props }, ref) => (
+  <CommandPrimitive.Item
+    ref={ref}
+    className={cn("relative flex cursor-default gap-2 select-none items-center rounded-sm px-2 py-1.5 text-sm outline-none data-[disabled=true]:pointer-events-none data-[selected=true]:bg-accent data-[selected=true]:text-accent-foreground data-[disabled=true]:opacity-50 [&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0", className)}
+    {...props}
+  />
+));
+CommandItem.displayName = CommandPrimitive.Item.displayName;
+
+const CommandEmpty = React.forwardRef<
+  React.ComponentRef<typeof CommandPrimitive.Empty>,
+  React.ComponentPropsWithoutRef<typeof CommandPrimitive.Empty>
+>((props, ref) => <CommandPrimitive.Empty ref={ref} className="py-6 text-center text-sm" {...props} />);
+CommandEmpty.displayName = CommandPrimitive.Empty.displayName;
+
+const CommandGroup = React.forwardRef<
+  React.ComponentRef<typeof CommandPrimitive.Group>,
+  React.ComponentPropsWithoutRef<typeof CommandPrimitive.Group>
+>(({ className, ...props }, ref) => (
+  <CommandPrimitive.Group ref={ref} className={cn("overflow-hidden p-1 text-foreground [&_[cmdk-group-heading]]:px-2 [&_[cmdk-group-heading]]:py-1.5 [&_[cmdk-group-heading]]:text-xs [&_[cmdk-group-heading]]:font-medium [&_[cmdk-group-heading]]:text-muted-foreground", className)} {...props} />
+));
+CommandGroup.displayName = CommandPrimitive.Group.displayName;
+
+export { Command, CommandInput, CommandList, CommandItem, CommandEmpty, CommandGroup };