fix(iOS, Tabs): tabBarTintColor on iPadOS (#3314)

## Description

Fixes setting tint color for the tab bar on iPadOS (>= 18).

<img width="2064" height="2752" alt="Simulator Screenshot - iPad Pro
13-inch (M4) - 2025-10-20 at 14 09 05"
src="https://github.com/user-attachments/assets/7efe321a-29c0-4eb0-b027-d87185cdcc7b"
/>


`tabBar.tintColor` does not work for the floating tab bar. [Apple
recommends](https://developer.apple.com/forums/thread/761056?answerId=798245022#798245022)
setting the tint color for the `UITabBarController`'s view - that's what
we do in this PR.

Unfortunately, when using the sidebar, tint color is set after a delay.
This is also reproducible in a native UIKit app and has been mentioned
in the same forum thread from the link above to happen [in native iPadOS
apps (e.g.
Numbers)](https://developer.apple.com/forums/thread/761056?answerId=798343022#798343022).


https://github.com/user-attachments/assets/8e1e0d9f-91be-47ce-9712-a80030bf3b9b

## Changes

- set tint color for `tabBarController.view`

## Test code and steps to reproduce

Run `TestBottomTabs` on an iPad.

## Checklist

- [x] Included code example that can be used to test this change
- [ ] Ensured that CI passes

Author: kligarski

ios/bottom-tabs/RNSTabBarAppearanceCoordinator.mm

@@ -3,6 +3,7 @@
 #import <React/RCTImageLoader.h>
 #import "RCTConvert+RNSBottomTabs.h"
 #import "RNSConversions.h"
+#import "RNSTabBarController.h"
 #import "RNSTabsScreenViewController.h"
 
 @implementation RNSTabBarAppearanceCoordinator
@@ -19,6 +20,10 @@ - (void)updateAppearanceOfTabBar:(nullable UITabBar *)tabBar
   // Step 1 - configure host-specific appearance
   tabBar.tintColor = hostComponentView.tabBarTintColor;
 
+  // Set tint color for iPadOS tab bar. This is the official way recommended by Apple:
+  // https://developer.apple.com/forums/thread/761056?answerId=798245022#798245022
+  hostComponentView.controller.view.tintColor = hostComponentView.tabBarTintColor;
+
   if (tabScreenCtrls == nil) {
     return;
   }