feat: add Base UI Tailwind component library

Add composable wrappers for 37 Base UI component families.

Expose primitive and convenience APIs with shared styling utilities.

Add the registry manifest, installer CLI, generation and export checks.

Include a smoke example covering primitive and shadcn-style imports.

src/components/ui/accordion/trigger.tsx

@@ -0,0 +1,26 @@
+"use client"
+
+import * as React from "react"
+import { Accordion as BaseAccordion } from "@base-ui/react/accordion"
+import { cn } from "@/lib/utils"
+
+export type AccordionTriggerProps = React.ComponentPropsWithoutRef<typeof BaseAccordion.Trigger> & {
+  className?: string
+}
+
+const BaseAccordionTrigger = BaseAccordion.Trigger as React.ElementType
+
+export const AccordionTrigger = React.forwardRef<HTMLElement, AccordionTriggerProps>(
+  ({ className, ...props }, ref) => (
+    <BaseAccordionTrigger
+      ref={ref}
+      className={cn(
+        "group flex w-full items-center justify-between gap-4 bg-transparent px-3 py-2 text-left text-sm font-normal text-neutral-950 select-none [&:not([data-disabled]):hover]:bg-neutral-100 focus-visible:relative focus-visible:z-1 focus-visible:outline-2 focus-visible:outline-solid focus-visible:outline-neutral-950 dark:focus-visible:outline-white dark:text-white dark:[&:not([data-disabled]):hover]:bg-neutral-800",
+        className,
+      )}
+      {...props}
+    />
+  ),
+)
+
+AccordionTrigger.displayName = "AccordionTrigger"