the vendoring machinery: one command reproduces the whole state

scripts/vendor.sh clones upstream, rewrites @/ imports to relative
paths, and applies scripts/apply-host.py. web/host.ts is ours and gets
placed into the vendored tree, because upstream declined it.

a script rather than a .patch, and that is not a preference. between
cfde698 and 5c83ac6 — one day — upstream changed an import line,
re-indented the component from 6 spaces to 8, and added an editAccess
guard. a context diff fails on all three, none of which concern us. so
every anchor matches structure with flexible whitespace and re-indents
to whatever it finds, and a missing anchor stops the run loudly.

all three prompt-export paths are wired, which is what upstream said a
complete version needs. the other two clipboard writes are ShareMenu's
share-link and ask-an-AI blurb, and the reason they are excluded is
written down so the count does not read as the same oversight twice.

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

web/vendor/components/PromptPanel.tsx

@@ -6,6 +6,7 @@ import { Doc, Palette, Platform, defaultPlatformOf } from "../lib/tokens";
 import { Icon } from "./M3Node";
 import { Field, IconBtn, Segmented } from "./ui";
 import { t, useLang } from "../lib/i18n";
+import { useHost } from "../lib/host";
 
 export function PromptPanel({
   doc,
@@ -22,6 +23,7 @@ export function PromptPanel({
   const generated = useMemo(() => buildPrompt(doc, widths, undefined, lang), [doc, widths, lang]);
   const edited = doc.promptEdit !== undefined;
   const text = edited ? doc.promptEdit! : generated;
+  const host = useHost();
   const [copied, setCopied] = useState(false);
 
   useEffect(() => {
@@ -32,6 +34,9 @@ export function PromptPanel({
 
   const copy = async () => {
     try {
+let handled = false;
+      try { handled = host.onExport?.(text, null) === true; } catch {}
+      if (handled) { setCopied(true); return; }
       await navigator.clipboard.writeText(text);
       setCopied(true);
     } catch {}