fix: Tab initialized with interactive=False cannot be updated to True

When a Tab's `interactive` prop changed via gr.Tab(interactive=True),
the `tabs` array in Tabs.svelte was updated by register_tab, but the
`visible_tabs` and `overflow_tabs` arrays (which the template actually
renders from) retained stale tab objects. These arrays are only
refreshed by handle_menu_overflow, which is async (awaits tick()) and
relies on DOM measurements.

Unlike `visible` changes—which trigger DOM structural changes in the
hidden measurement container, cascading through element bindings to
re-trigger handle_menu_overflow—`interactive` changes cause no DOM
structural changes, so visible_tabs never gets the updated tab data.

The fix adds a synchronous reactive block that keeps visible_tabs and
overflow_tabs tab objects in sync with the canonical tabs array whenever
any tab property changes.

Closes #13033

Signed-off-by: Tan <alvinttang@gmail.com>

Author: gambletan

js/tabs/shared/Tabs.svelte

@@ -32,6 +32,26 @@
 
 	$: has_tabs = tabs.length > 0;
 
+	// Keep visible_tabs and overflow_tabs in sync with tabs data.
+	// handle_menu_overflow determines which tabs go into which list (based on
+	// DOM measurements), but it is async (awaits tick()) so property updates
+	// like interactive changes can be missed. This reactive block ensures the
+	// tab objects inside visible_tabs/overflow_tabs stay current.
+	$: {
+		if (tabs) {
+			visible_tabs = visible_tabs.map((vt) => {
+				if (!vt) return vt;
+				const updated = tabs.find((t) => t?.id === vt.id);
+				return updated ?? vt;
+			});
+			overflow_tabs = overflow_tabs.map((ot) => {
+				if (!ot) return ot;
+				const updated = tabs.find((t) => t?.id === ot.id);
+				return updated ?? ot;
+			});
+		}
+	}
+
 	let tab_nav_el: HTMLDivElement;
 
 	const selected_tab = writable<false | number | string>(