feat(scenarios): type-to-confirm delete modal, replacing browser confirm()

Swap the native confirm() popup for the app's shadcn Dialog pattern
(as in Settings → Danger Zone): the destructive button stays disabled
until the user types "delete" (case-insensitive), with Enter-to-submit
and a proper explanation of what's removed. On a delete error the
dialog closes so the inline error is visible.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/app/portfolio/[slug]/(portfolio)/scenarios/[scenarioId]/DetailActions.tsx

@@ -4,6 +4,13 @@ import { useState } from "react";
 import Link from "next/link";
 import { useRouter } from "next/navigation";
 import { useMutation } from "@tanstack/react-query";
+import {
+  Dialog,
+  DialogContent,
+  DialogTitle,
+  DialogFooter,
+} from "@/app/shadcn_components/ui/dialog";
+import { Button } from "@/app/shadcn_components/ui/button";
 
 const btn =
   "rounded-xl border border-gray-200 bg-white px-4 py-2 text-sm font-semibold text-brandblue transition hover:bg-gray-50 disabled:cursor-not-allowed disabled:opacity-45";
@@ -36,6 +43,9 @@ export function DetailActions({
   const [editing, setEditing] = useState(false);
   const [draftName, setDraftName] = useState(initialName);
   const [error, setError] = useState<string | null>(null);
+  const [deleteOpen, setDeleteOpen] = useState(false);
+  const [deleteConfirmation, setDeleteConfirmation] = useState("");
+  const deleteConfirmed = deleteConfirmation.trim().toLowerCase() === "delete";
 
   const rename = useMutation({
     mutationFn: async (newName: string) => {
@@ -68,7 +78,10 @@ export function DetailActions({
       if (!res.ok) throw new Error((await res.json()).error ?? "Delete failed");
     },
     onSuccess: () => router.push(`/portfolio/${portfolioId}/scenarios`),
-    onError: (e: Error) => setError(e.message),
+    onError: (e: Error) => {
+      setError(e.message);
+      setDeleteOpen(false);
+    },
   });
 
   return (
@@ -162,17 +175,12 @@ export function DetailActions({
           <>
             <button
               className={`${btn} border-red-100 !text-red-800 hover:!bg-red-50`}
-              disabled={remove.isLoading}
               onClick={() => {
-                if (
-                  confirm(
-                    `Delete "${name}"?\n\nNothing has been modelled against it — only the configuration is removed. This can't be undone.`,
-                  )
-                )
-                  remove.mutate();
+                setDeleteConfirmation("");
+                setDeleteOpen(true);
               }}
             >
-              {remove.isLoading ? "Deleting…" : "Delete scenario"}
+              Delete scenario
             </button>
             <span className="max-w-[52ch] text-[13px] text-gray-400">
               Nothing has been modelled against this scenario — deleting removes
@@ -182,6 +190,51 @@ export function DetailActions({
         )}
       </div>
       {error && <div className="mt-3 text-[13px] text-red-800">{error}</div>}
+
+      <Dialog open={deleteOpen} onOpenChange={setDeleteOpen}>
+        <DialogContent className="max-w-md">
+          <DialogTitle className="font-manrope text-lg font-extrabold text-brandblue">
+            Delete “{name}”?
+          </DialogTitle>
+          <p className="text-sm text-gray-600">
+            Nothing has been modelled against this scenario — deleting removes
+            only the configuration. This can&apos;t be undone.
+          </p>
+          <div>
+            <label
+              htmlFor="delete-confirmation"
+              className="mb-1.5 block text-sm text-gray-600"
+            >
+              To confirm, type <strong className="text-brandblue">delete</strong>
+            </label>
+            <input
+              id="delete-confirmation"
+              autoFocus
+              type="text"
+              value={deleteConfirmation}
+              placeholder="delete"
+              onChange={(e) => setDeleteConfirmation(e.target.value)}
+              onKeyDown={(e) => {
+                if (e.key === "Enter" && deleteConfirmed && !remove.isLoading)
+                  remove.mutate();
+              }}
+              className="w-full rounded-xl border border-gray-200 px-3 py-2 text-sm outline-none transition focus:border-red-300 focus:shadow-[0_0_0_3px_rgba(185,28,28,.10)]"
+            />
+          </div>
+          <DialogFooter>
+            <Button variant="outline" onClick={() => setDeleteOpen(false)}>
+              Cancel
+            </Button>
+            <Button
+              className="bg-red-700 hover:bg-red-800"
+              disabled={!deleteConfirmed || remove.isLoading}
+              onClick={() => remove.mutate()}
+            >
+              {remove.isLoading ? "Deleting…" : "Delete scenario"}
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
     </>
   );
 }