Onboard a source with an agent

You are wiring up a webhook source for Splendor. Use the Splendor admin API to
create a source and an ingest token, help me configure the provider's webhook
to send events to it, then confirm the events arrive.

Values:
- SPLENDOR_API_BASE   = https://api.withsplendor.com
- SPLENDOR_TENANT_ID  = <my tenant id>
- SPLENDOR_TOKEN      = <a tenant-admin bearer token, or a platform API key scoped to this tenant>

Admin calls use these headers:
  Authorization: Bearer $SPLENDOR_TOKEN
  X-Splendor-Tenant-Id: $SPLENDOR_TENANT_ID

Steps (show me each request before you send it, and wait for my go-ahead on writes):
1. Ask me which provider to connect and a short dataset name.
2. Create a hosted source:
     POST $SPLENDOR_API_BASE/v1/admin/hosted-sources
     { "source_key": "<provider>-events", "name": "<Provider> events",
       "dataset_id": "<dataset>", "source_type": "hosted" }
   Save the returned source_id and source_key.
3. Mint an ingest token:
     POST $SPLENDOR_API_BASE/v1/admin/sources/<source_id>/ingest-token
   Save the plaintext token (shown once). Treat it like a password.
4. The logs endpoint takes a batch — a JSON array (Content-Type
   application/json) or newline-delimited JSON — with the ingest token as a
   bearer credential (no tenant header). A webhook sends one object at a time
   and usually can't set that header, so propose a small relay: a function that
   receives the provider's event, wraps it as a one-element array, and POSTs to
     $SPLENDOR_API_BASE/v1/ingest/sources/<source_key>/logs
   with `Authorization: Bearer <the ingest token>`. Give me the relay code and
   tell me to point the provider's webhook at the relay's URL. (If the provider
   can already send an array body and a custom Authorization header, skip the
   relay and point it straight at the logs endpoint.)
5. After I trigger a test event, verify it landed:
     GET $SPLENDOR_API_BASE/v1/ingest/runs?dataset_id=<dataset>
   then run a search to confirm the data is queryable.