Ingestable: use ingest_path for local paths

This way we don't error-out when a path is a directory. That said, we're
still only including the root in sidx.db (e.g. manifests/ but not
manifests/*.json). We should change that next.

Also renamed "blob_id" to "blake3_id" because datasette has a special
branch for ${column}_id referencing a table that contains ${column}

src/q/latest-download.sql

@@ -5,10 +5,10 @@ SELECT
 FROM
     sidx_uri_sample AS s,
     sidx_uri AS u,
-    sidx_blob AS b
+    sidx_blake3 AS b
 ON
     s.uri_id = u.id
-    AND s.blob_id = b.id
+    AND s.blake3_id = b.id
 WHERE
     u.uri = ?
 ORDER BY