fix(workspace): tighten link preview card, slash menu matching/scrolling, and Enter on last empty bullet

frontend/src/lib/linkPreview.ts

@@ -16,12 +16,12 @@ export interface LinkPreview {
   ok: boolean;
 }
 
-// First plain https address in a text (not inside [text](url), not right after "(" or "<")
-const BARE_URL_RE = /(^|[\s])(https:\/\/[^\s<>()\]]+[^\s<>()\].,;:!?'"])/;
+// Entire bullet content (trimmed) is a single plain https address
+const CARD_URL_RE = /^https:\/\/[^\s<>()\]]+[^\s<>()\].,;:!?'"]$/;
 
-export function firstBareUrl(content: string): string | null {
-  const m = BARE_URL_RE.exec(content || '');
-  return m ? m[2] : null;
+export function linkCardUrl(content: string): string | null {
+  const trimmed = (content || '').trim();
+  return CARD_URL_RE.test(trimmed) ? trimmed : null;
 }
 
 /** Replaces the address by a named link, which shows no preview. */