v0.9.10 Maintenance Release

This maintenance release fixes manual cookie authentication for accounts using the Gemini Notebook rebrand host.

Fixed

Manual cookie login now verifies imported cookies against the configured host and the personal notebook.google.com host when no override is configured.
The authenticated host is persisted in the profile so subsequent CLI and MCP requests use the correct endpoint instead of falling back to notebooklm.google.com.
Manual login now reports rejected cookies and network verification failures instead of claiming authentication succeeded.
Authentication documentation now explains host detection, the explicit NOTEBOOKLM_BASE_URL workaround, and the static nature of cookie files.

Thanks to @afonsoft for the detailed headless reproduction, fresh-cookie comparison, and root-cause follow-up in issue #292.

Local CI-equivalent checks: 1,407 tests passed, 38 skipped, and 1 deselected; Ruff lint and formatting passed.
Windows focused regression suite on Jabella: 5 tests passed.
The two unrelated Windows full-suite failures were reproduced identically on a pristine main checkout and are outside this release's changes.