docs: consolidate AGENTS.md; reference skills from README.md

[szuperaz]

🎯 Goal

• Consolidate AGENTS.ms and CLAUDE.md -> CLAUDE.md will stay only as a reference
• Add skill reference to README.md file
• Remove stale references/info

🛠 Implementation details

🎨 UI Changes

iOS

Before	After

Android

Before	After

🧪 Testing

☑️ Checklist

• I have signed the Stream CLA (required)
• PR targets the develop branch
• Documentation is updated
• New code is tested in main example apps, including all possible scenarios
  • SampleApp iOS and Android
  • Expo iOS and Android