feat(forms): visible public link + one-click Copy on member and admin lists

- shared components/forms/copy-link-button.tsx (one control, no drift):
  copies the absolute /f/<space>/<slug> URL, check-mark + toast feedback
- admin /forms list: Copy link button on every published public form
- member /my-forms list: shows the /f/<space>/<slug> path and a Copy
  button for public forms; row restructured so the button is not nested
  in the row link
- members-only forms show no public link (correct: they have none)

337 tests; build verified. Local commit (deploy on your word).

components/forms/copy-link-button.tsx

@@ -0,0 +1,33 @@
+'use client'
+
+import { useState } from 'react'
+import { Check, Copy } from 'lucide-react'
+import { toast } from 'sonner'
+import { Button } from '@/components/ui/button'
+
+// One reusable copy-to-clipboard control for a form's public link. Shared by
+// the admin forms list and the member forms list so the behaviour and styling
+// never drift.
+export function CopyLinkButton({ path, label = 'Copy link' }: { path: string; label?: string }) {
+  const [copied, setCopied] = useState(false)
+
+  async function copy() {
+    const url =
+      typeof window !== 'undefined' ? `${window.location.origin}${path}` : path
+    try {
+      await navigator.clipboard?.writeText(url)
+      setCopied(true)
+      toast.success('Public link copied')
+      setTimeout(() => setCopied(false), 2000)
+    } catch {
+      toast.error('Could not copy — copy it manually')
+    }
+  }
+
+  return (
+    <Button size="sm" variant="secondary" onClick={copy} aria-label={label}>
+      {copied ? <Check className="size-4" /> : <Copy className="size-4" />}
+      {label}
+    </Button>
+  )
+}