Manual test pass: MongoDB + Elasticsearch backend

[smunini]

Summary

Run the manual testing pass in MANUAL_TESTING_MATRIX.md for the MongoDB + Elasticsearch backend (HFS_STORAGE_BACKEND=mongo-es) and record the results in this issue.

The matrix is organised backend-first: every backend gets the same T0 through T8 sequence. This issue covers one row of that matrix.

Procedure

Follow MANUAL_TESTING_MATRIX.md sections 2 through 12 in order, using the mongo-es row of the per-backend environment table in section 5.

Infrastructure: start MongoDB 7.0 and Elasticsearch 8.15.0 per section 4. Infrastructure: start Elasticsearch 8.15.0 per section 4. Set HFS_COMPOSITE_SYNC_MODE=synchronous and HFS_ELASTICSEARCH_WRITE_REFRESH=wait_for (section 5 common env) so searches are read-your-write during T2 and T3. Confirm in the log or with HFS_LOG_LEVEL=debug that T3 searches are served by Elasticsearch, and that curl localhost:9200/_cat/indices/hfs* document counts match the T2 totals. Note: Bulk Data $export (T4) has no job store on MongoDB and is expected to return 501; record that cell as N/A rather than as a failure.

• T0 Build with the CI selection: cargo build --workspace --all-features --release
• T1 Start HFS with HFS_STORAGE_BACKEND=mongo-es HFS_MONGODB_URI=mongodb://localhost:27017 HFS_MONGODB_DATABASE=helios HFS_ELASTICSEARCH_NODES=http://localhost:9200 and confirm /health, /metadata, and /ui
• T2 Import at least 10,000 resources from the Synthea bulk_1k archive (record wall-clock time, bundle count, resource total)
• T3 One search per type: string, token, date, number, quantity, reference, uri, composite, special, plus chained, reverse-chained, _include/_revinclude, _sort, paging, _content, POST search
• T4 Bulk Data $export: system, patient, group; all three NDJSON format spellings; unsupported format returns 400; UI /ui/bulk-export
• T5 Create a ViewDefinition via API and via /ui/sql/view-definitions; examine $sql-run output in json, csv, ndjson, parquet
• T6 $sql-export with a ViewDefinition subject, a SQLQuery Library subject, and a SQLView Library subject, cycling all four formats; UI /ui/sql/export
• T7 Create a SubscriptionTopic (R4 backport Basic) and rest-hook Subscription, trigger notifications, verify delivery, $status, $events
• T8 Verify the /ui/subscriptions activity dashboard (cards, table row, sparkline, failure streak, rehydration after restart)

Results to attach

• The filled-in mongo-es row of the matrix table from section 1 of MANUAL_TESTING_MATRIX.md
• build.log tail, hfs-mongo-es.log, import-mongo-es.log, and the T2 timing line
• One T4 manifest and one T6 result manifest
• Screenshots of /ui after import, /ui/sql/export with a completed card, and /ui/subscriptions after T8
• For any failure: the request, the OperationOutcome, the log excerpt, and a link to the issue filed for it

Acceptance criteria

• Every T0 through T8 cell for the mongo-es row is marked pass, or marked fail with a linked issue, or marked N/A where section 1's expected-support table says the capability is unsupported on this backend
• Results and artifacts listed above are attached to this issue