Fix issue #6277 where TextMessage was used but not imported in three code cells
of the custom agents documentation, causing NameError when users run the examples.

Changes:
- Add TextMessage to imports in ArithmeticAgent section
- Add TextMessage to imports in GeminiAssistantAgent section
- Add TextMessage to imports in Declarative GeminiAssistantAgent section

The CountDownAgent section already had the correct import.

Fixes #6277

…_team.py

- Add specific WebSocketDisconnect exception handling in _user_input function
- Handle client disconnects during message processing without RuntimeError
- Prevent attempts to send messages to closed WebSocket connections
- Add graceful cleanup when clients disconnect while waiting for input

Fixes #6280: Heavy use of broad Exceptions leads to incorrect error handling

The previous implementation caught WebSocketDisconnect with broad Exception
handlers and re-raised as RuntimeError, preventing graceful disconnect handling.
This fix allows proper exception propagation and clean connection termination.

…stallation guide- Fix version format from 0.4.0-dev-1 to 0.4.0-dev.1 for all packages- Remove reference to non-existent Microsoft.AutoGen.Extensions package- Add correct extension packages: Aspire, MEAI, and SemanticKernel- Fix typo: RuntimeGatewway -> RuntimeGateway- Improve documentation structure with clear section headersFixes #6244"

This reverts commit 6d9fb2e.