Session does not refresh if there is no password manager

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Describe the bug

If there is no password manager (seahorse, kwallet, etc.), and ownCloud Desktop is logged in via OIDC in a browser, it is not able to extend the session, and the session logs out after some time. Note that the process keeps running and this does not require saving credentials.

Expected behavior

If there is no password manager, ownCloud Desktop extends the session using in-memory credentials, as long as the process keeps running. This does not require saving credentials anywhere (#12444).

Steps to reproduce the issue

0. Ensure no password manager is installed.
1. Launch ownCloud and log in.
2. Wait until the first token expires.
3. Look at ownCloud. It fails to extend the session.

Screenshots

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Logs

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Client version number

5.3.2 1e2be1dee795e48d3a8d42ea5a6a419f1c83556c

Desktop environment (Linux only)

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Client package version and origin (Linux only)

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Installation path (Windows only)

No response

Server information

oCIS 7.3.0

Additional context

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Start by reproducing the issue on ownCloud Desktop 5.3.2 with no password manager and an OIDC browser login, then trace the session-extension and token-refresh flow. Compare the behavior when credentials are not persisted with the expected in-memory path. Done means the session refreshes after the first token expiry while the process remains running, without saving credentials.