Reject register-only configs that leave the shared retry interval at the
zero value so failed registration attempts cannot spin in a tight loop.
Cover the regression in tests and make the register-only integration test
explicit about its retry interval.
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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Keep the NAS-side runtime bounded to the configured export path,
make WebDAV and registration behavior env-driven, and add runtime
coverage so the first storage loop can be verified locally.
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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>