Bug: Stale Account Identity in Session Telemetry after Account Switch within the same thread

What issue are you seeing?

Description
A bug was identified where credit usage and telemetry events are attributed to the wrong account when a user switches accounts but continues chatting in an existing thread.

What steps can reproduce the bug?

1. Log in to Account A.
2. Start a chat thread and send a message. Usage is correctly billed to Account A.
3. Log out or switch to Account B.
4. Continue the conversation in the same thread from Step 2.
5. Observed Behavior: Usage and telemetry for the new messages are still attributed to Account A.
6. Expected Behavior: Usage should be attributed to the currently logged-in account (Account B).

Note: If a brand new thread is started after switching to Account B, the usage is correctly attributed to Account B.

What is the expected behavior?

_No response_

Additional information

_No response_