SAP coordination: pilot agency onboarding

### What
Identify and onboard one pilot agency that has datasets in both Data.gov and the SAP, walk them through the new single-submission workflow, and confirm the end-to-end process works.

### Why
A real-world test with one willing agency validates the technical approach before we scale. It also surfaces any gaps in the agency-facing guidance.

### Done When
- [ ] At least one pilot agency is identified and has agreed to participate
- [ ] The agency has set the SAP flag on their relevant dataset records in Data.gov
- [ ] The SAP portal has successfully harvested those flagged records from Data.gov
- [ ] The agency has confirmed they did not need to submit separately to the SAP portal
- [ ] Any issues encountered are documented with resolutions

### Notes
- Ideal pilot agency: one that already publishes to both systems and has a willing CDO or data contact