Add the first control-plane UI over the verified backend seam so exports,
issued DAV credentials, and Finder instructions can be exercised from the
running stack.
Split node enrollment from export sync and issue Finder-compatible DAV
credentials so the stack proves the real backend seam before any web UI
consumes it.
Protect the control-plane API with explicit bearer auth, add node-scoped
registration/heartbeat credentials, and make export mount paths an explicit
contract field so mount profiles stay correct across runtimes.
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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>