fix: remove duplicate ESC handlers causing double history.back()

AboutModal, ProfileModal, and ShareDialog each had their own
useEscapeKey hook AND were handled by the global ESC handler in
App.tsx. When ESC was pressed, both fired synchronously, calling
history.back() twice — navigating past the current page instead
of just closing the modal.

Removed the per-modal useEscapeKey calls since the global handler
in App.tsx already manages ESC priority for all modals.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/components/ShareDialog.tsx

@@ -5,7 +5,6 @@
 
 import { Check, Copy, Link2, X } from "lucide-react";
 import { useTranslation } from "react-i18next";
-import { useEscapeKey } from "../hooks/useEscapeKey";
 
 export interface ShareDialogProps {
 	show: boolean;
@@ -44,7 +43,7 @@ export function ShareDialog({
 	const closeLabel = t("common.close");
 	const copyLabel = shareCopied ? t("share.copied") : t("share.copyLink");
 
-	useEscapeKey(show, onClose);
+	// ESC is handled by the global handler in App.tsx to avoid double history.back()
 
 	if (!show) return null;