Add two agents that allow for an agentic flow

[eneufeld]

What it does

It provides two new agents that allow for a fully agentic flow.

How to test

In order to test use Theia Dev and give it a bug/description of what to do.
It should give you an analysis and wait for your confirmation. Afterwards it should delegate to the TheiaDevCode agents and let it do the heavy lifting.

I suggest to add these entries to your settings:

"ai-features.modelSettings.requestSettings": [
    {
      "scope": {
        "modelId": "claude-sonnet-4-5-20250929",
        "agentId": "theia_dev"
      },
      "requestSettings": {
        "max_tokens": 40000,
        "temperature": 1,
        "thinking": {
          "type": "enabled",
          "budget_tokens": 20000
        }
      }
    }
  ],
  "ai-features.mcp.mcpServers": {
    "Context7": {
      "type": "http",
      "serverUrl": "https://mcp.context7.com/mcp",
      "autostart": true
    },
    "github": {
      "type": "http",
      "serverUrl": "https://api.githubcopilot.com/mcp/",
      "serverAuthToken": "<YOUR_TOKEN>"
    }
  }

Follow-ups

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

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[JonasHelming]

We have a GitHub Agent now, should we instead delegate to it?

[eneufeld]

maybe, I didn't test it yet

[JonasHelming]

I like the agent design, great job! One open comment about the GitHub agent above.

However, I would not commit the settings.

enableAI: => unrelated

modelSettings => unrelated, add maybe as a recommendation in the PR description

git_mcp_server => not used

Context7 => mention in the PR but switch to the remote version (https://github.com/upstash/context7) (we might consider to install this by default)

Playwright => not used

GitHub => can be delegated to agent, see above

Playwright-visual => not used

After this, I would merge this to allows Theia developers to test it.

[eneufeld]

enableAI: => unrelated

✔️

modelSettings => unrelated, add maybe as a recommendation in the PR description

This is needed as I find configuring the theia_dev to using thinking is important

git_mcp_server => not used

✔️

Context7 => mention in the PR but switch to the remote version (https://github.com/upstash/context7) (we might consider to install this by default)

✔️ Nice find, I was not aware there is a remote version.

Playwright => not used

✔️

GitHub => can be delegated to agent, see above

Ok, would be added via the agent then.

Playwright-visual => not used

✔️

[JonasHelming]

@eneufeld I am still not sure about adapting the default settings for all Theia devs. Let's remove the settings changes all together and just document them in the PR so that people trying this agent can pick them up. Please also open a follow-up ticket about the thinking settings. If this is important, we should solve it generically I think.

[eneufeld]

Created follow up for thinking/reasoning models: #16642