chore: add configurable CIMD support for Plane OAuth provider (#143)

* chore: disable cimd in OAuth provider

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* chore: add enable_cimd option to OAuth provider settings

* chore: update enable_cimd option

* chore: enable CIMD option in OAuth provider configuration

* chore: add Claude.ai web client URL to OAuth provider configuration

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Co-authored-by: Surya Prashanth <prashantsurya002@gmail.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>