feat(capa): add Close CAPA button for HSE after verification

Verified CAPAs now show a Close button on the detail page for
HSE/admin, transitioning status to closed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components/capa/close-capa-button.tsx

@@ -0,0 +1,49 @@
+'use client'
+
+import { useState } from 'react'
+import { useRouter } from 'next/navigation'
+
+interface Props {
+  capaId: string
+}
+
+export function CloseCapaButton({ capaId }: Props) {
+  const router = useRouter()
+  const [loading, setLoading] = useState(false)
+  const [error, setError] = useState<string | null>(null)
+
+  async function handleClose() {
+    if (!confirm('Close this CAPA? This marks it as fully resolved.')) return
+    setLoading(true)
+    setError(null)
+    const res = await fetch(`/ims/api/capa/${capaId}`, {
+      method: 'PATCH',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ status: 'closed' }),
+    })
+    if (!res.ok) {
+      setError('Failed to close CAPA. Please try again.')
+      setLoading(false)
+      return
+    }
+    router.push('/hse/capa')
+    router.refresh()
+  }
+
+  return (
+    <div className="border border-gray-200 rounded-xl p-5 space-y-3 bg-green-50">
+      <h3 className="text-sm font-semibold text-gray-800">Close CAPA</h3>
+      <p className="text-sm text-gray-600">
+        This CAPA has been verified as effective. Close it to mark it fully resolved.
+      </p>
+      {error && <p className="text-sm text-red-600">{error}</p>}
+      <button
+        onClick={handleClose}
+        disabled={loading}
+        className="w-full bg-green-700 text-white rounded-lg py-2 text-sm font-semibold hover:bg-green-800 disabled:opacity-50"
+      >
+        {loading ? 'Closing…' : 'Close CAPA'}
+      </button>
+    </div>
+  )
+}