test: add transparency stream scenarios

[Steake]

Summary

• add tests for starting a transparency session and verifying step streaming
• test automatic websocket reconnection after a simulated interruption

Testing

• npm test tests/transparency-streams.spec.js (fails: Playwright Test did not expect test.describe() to be called here)

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https://chatgpt.com/codex/tasks/task_e_68b4b19dc8088332ab36c65bebd05b10

[Steake]

@copilot please resolve the merge conflicts

[Copilot]

Pull Request Overview

This PR adds comprehensive tests for transparency stream functionality using Playwright. The tests verify that the application can start transparency sessions and stream steps in real-time, as well as handle WebSocket reconnection scenarios.

• Adds test coverage for starting transparency sessions and verifying live step streaming
• Implements WebSocket reconnection testing with simulated server interruptions
• Uses mock network responses to simulate backend API interactions

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[Steake]

@copilot please resolve merge conflicts