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## Why are these changes needed?

It is useful to rapidly validate any changes to a team structure as
teams are built either via drag and drop or by modifying the underlying
spec

You can now “validate” your team. The key ideas are as follows
- Each team is based on some Component Config specification which is a
pedantic model underneath.
- Validation is 3 pronged based on a ValidatorService class 
    - Data model validation (validate component schema)
    - Instantiation validation (validate component can be instantiated)
- Provider validation, component_type validation (validate that provider
exists and can be imported)
- UX: each time a component is **loaded or saved**, it is automatically
validated and any errors shown (via a server endpoint). This way, the
developer immediately knows if updates to the configuration is wrong or
has errors.

> Note: this is different from actually running the component against a
task. Currently you can run the entire team. In a separate PR we will
implement ability to run/test other components.

<img width="1360" alt="image"
src="https://github.com/user-attachments/assets/d61095b7-0b07-463a-b4b2-5c50ded750f6"
/>

<img width="1368" alt="image"
src="https://github.com/user-attachments/assets/09a1677e-76e8-44a4-9749-15c27457efbb"
/>

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solves. -->

## Related issue number

Closes #4616 

<!-- For example: "Closes #1234" -->

## Checks

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https://microsoft.github.io/autogen/. See
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introduced in this PR.
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Add clear notes on how to specify api key and modifying specifications
in AGS.
Add diagrams explaining how to switch between visual builder and JSON
mode

## Why are these changes needed?

<!-- Please give a short summary of the change and the problem this
solves. -->


![teambuilder](https://github.com/user-attachments/assets/9eede334-7f60-4c87-bec6-cf41839ba231)


## Related issue number

<!-- For example: "Closes #1234" -->

@nour-bouzid 

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introduced in this PR.
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It is often helpful to inspect the raw request and response to/from an
LLM as agents act.
This PR, does the following:

- Updates TeamManager to yield LLMCallEvents from core library
- Run in an async background task to listen for LLMCallEvent JIT style
when a team is run
   - Add events to   an async queue and 
- yield those events in addition to whatever actual agentchat
team.run_stream yields.
- Update the AGS UI to show those LLMCallEvents in the messages section
as a team runs
   - Add settings panel to show/hide llm call events in messages. 
- Minor updates to default team

<img width="1539" alt="image"
src="https://github.com/user-attachments/assets/bfbb19fe-3560-4faa-b600-7dd244e0e974"
/>
<img width="1554" alt="image"
src="https://github.com/user-attachments/assets/775624f5-ba83-46e8-81ff-512bfeed6bab"
/>
<img width="1538" alt="image"
src="https://github.com/user-attachments/assets/3becbf85-b75a-4506-adb7-e5575ebbaec4"
/>


## Why are these changes needed?

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solves. -->

## Related issue number

<!-- For example: "Closes #1234" -->

Closes #5440 

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introduced in this PR.
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## Why are these changes needed?

- Add ability to test teams in Team Builder view 
- Update Gallery (add deep research default team, fix bug with gallery
serialization)
- UI fixes 
   -  improve drag drop component experience 
- improve new session experience (single click rather than 3 clicks to
create a session)
   - fix bug with stop reason not being shown in some cases

<img width="1738" alt="Image"
src="https://github.com/user-attachments/assets/4b895df2-3bad-474e-bec6-4fbcbf1c4346"
/>

<img width="1761" alt="Image"
src="https://github.com/user-attachments/assets/65f52eb9-e926-4168-88fb-d2496c159474"
/>

<!-- Please give a short summary of the change and the problem this
solves. -->

## Related issue number

Closes #5392

<!-- For example: "Closes #1234" -->

## Checks

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https://microsoft.github.io/autogen/. See
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build and test documentation locally.
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introduced in this PR.
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This PR does the following: 

- Fix warning messages in AGS on launch.
- Improve Cli message to include app URL on startup from command line
- Minor improvements default gallery generator. (add more default tools)
- Improve new session behaviour.



## Related issue number

Closes #5097

## Checks