[Bug] Default model selection ignored; new sessions use most recently selected model instead

Bug Description
When selecting a model, Opus 5 is currently shown as the Default model. This is misleading because users naturally assume that if Opus 5 is set as their default, every new session they start will use Opus 5. However, that is not what actually happens. For example, even if a user has selected Opus 5 as the default, if they temporarily select Fabul 5 in another existing session, the next new session they open will start with Fabul 5 instead of Opus 5. In other words, the system appears to use the most recently selected model for new sessions, rather than the model that the user explicitly selected as their Default. As a result, once a user who has Opus 5 set as their default uses Fabul 5 even once in another session, subsequent new sessions may continue to start with Fabul 5. This behavior is misleading and can cause users to unintentionally use a different model and consume significantly more tokens than expected. If a model is explicitly marked and selected as the user's Default, new sessions should always start with that default model unless the user intentionally changes their default setting. Please investigate and fix this behavior.

Environment Info

• Platform: win32
• Terminal: null
• Version: 2.1.233
• Feedback ID: 56d21b90-5a5c-4014-8e47-b88523977824

Errors

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