[Enhancement]Remove IdleTimer handling from UI

[ipavlidakis]

🎯 Goal

This PR removes the UIApplication.shared.isIdleTimerDisabled handling from UI and makes it an SDK responsibility. That should make UI creation simpler and less error prone.

☑️ Contributor Checklist

• I have signed the Stream CLA (required)
• This change follows zero ⚠️ policy (required)
• This change should receive manual QA
• Changelog is updated with client-facing changes
• New code is covered by unit tests
• Comparison screenshots added for visual changes
• Affected documentation updated (tutorial, CMS)

[github-actions]

Public Interface

🚀 No changes affecting the public interface.

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
StreamVideo	7.9 MB	7.91 MB	+1 KB	🟢
StreamVideoSwiftUI	2.26 MB	2.26 MB	0 KB	🟢
StreamVideoUIKit	2.38 MB	2.38 MB	0 KB	🟢
StreamWebRTC	9.85 MB	9.85 MB	0 KB	🟢

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
69.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud