Allow Theia Coder Agent Mode to launch Apps

[JonasHelming]

What it does

Adds launch configuration support to the AI Coder agent, enabling it to start and manage long-running applications for testing and user interaction.

• Added launch configuration functions (listLaunchConfigurations, runLaunchConfiguration, stopLaunchConfiguration) to the coder agent's toolset
• Added "Start Theia Default (Browser backend, no debug)" launch config that the agent can reliably identify and use
• Updated project-info prompt to reference the new launch config

How to test

1. Start Theia and open the AI chat
2. Ask the Coder agent to start the application
3. Verify the agent uses launch configurations instead of blocking tasks

Follow-ups

Check the new AppTester and /with-app-testing for consistency @sgraband
(Is tested it once, it seems to work, but please check)

Breaking changes

• This PR introduces breaking changes and requires careful review. If yes, the breaking changes section in the changelog has been updated.

Attribution

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines
• User-facing text is internationalized using the nls service (for details, please see the Internationalization/Localization section in the Coding Guidelines)

Reminder for reviewers

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