Fix Dotnet AF sample

[lsl-2020]

1. Change ChatOptions.Temperature from 0.2 to 1 because some models (such as o-series and preview ones such as gpt-5.2-chat) does not support Temperature parameter so it has to be default 1.

2. Add BEARER_TOKEN in launchsettings.json so that a365 develop get-token can update it automatically for local debugging. (Refer to recent change in Fix bearer token approach for Dotnet AF Sample #170)

[Copilot]

Pull request overview

Updates the .NET Agent Framework sample to improve compatibility with models that require default temperature settings and to support local debugging workflows that rely on an updatable BEARER_TOKEN.

Changes:

• Set ChatOptions.Temperature to 1 (with explanatory comments) to avoid model incompatibilities with non-default temperature values.
• Add Properties/launchSettings.json including BEARER_TOKEN for local debugging and token injection tooling.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
dotnet/agent-framework/sample-agent/Properties/launchSettings.json	Adds a debug profile with environment variables for Development, including BEARER_TOKEN.
dotnet/agent-framework/sample-agent/Agent/MyAgent.cs	Updates chat options to use Temperature = 1 and documents model constraints.

[lsl-2020]

Found the dev tools has updated the hit. Closing this now.

Detecting platform in: D:\playground\Agent365-Samples\dotnet\agent-framework\sample-agent
Detected .NET project (found 1 project file(s))
To use the bearer token in your .NET application, add it to launchSettings.json:
  Properties/launchSettings.json > profiles > [profile-name] > environmentVariables > BEARER_TOKEN
Token acquired successfully!