feat(examples): refresh react tutorial app for v14

[oliverlaz]

🎯 Goal

Update the React tutorial example app so it matches the upcoming v14 SDK APIs and is easier to explore locally.

🛠 Implementation details

• migrate the tutorial step apps from MessageInput to MessageComposer
• replace old prop-based customization examples with WithComponents patterns
• update the tutorial examples for current channel-list, attachment, emoji, and livestream APIs
• point the local tutorial app at the local stream-chat-react checkout and current CSS entrypoint
• add a root tutorial browser with a sidebar step list and a live preview pane
• move the browser shell styles into examples/tutorial/src/tutorial-main.css
• update the tutorial Vite config and README to support the new browser flow

🎨 UI Changes

• adds a tutorial browser shell with a left sidebar for step navigation and a right preview pane
• keeps the individual tutorial steps runnable while making it easier to switch between them quickly

[github-actions]

Size Change: 0 B

Total Size: 621 kB

ℹ️ View Unchanged

Filename	Size
dist/cjs/audioProcessing.js	1.32 kB
dist/cjs/emojis.js	2.96 kB
dist/cjs/index.js	237 kB
dist/cjs/mp3-encoder.js	1.27 kB
dist/cjs/WithAudioPlayback.js	45.5 kB
dist/css/emoji-replacement.css	456 B
dist/css/index.css	47.3 kB
dist/es/audioProcessing.mjs	1.31 kB
dist/es/emojis.mjs	2.47 kB
dist/es/index.mjs	235 kB
dist/es/mp3-encoder.mjs	756 B
dist/es/WithAudioPlayback.mjs	45.3 kB

_{compressed-size-action}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.12%. Comparing base (3f09362) to head (7f48354).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3078   +/-   ##
=======================================
  Coverage   79.12%   79.12%           
=======================================
  Files         426      426           
  Lines       12162    12162           
  Branches     3917     3917           
=======================================
  Hits         9623     9623           
  Misses       2539     2539           

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