fix(ingestion): batch history lookups instead of adding an index

An index on execution_run_outputs would make the library unopenable by
older builds, whose schema check refuses any extra index there. The
migration and the schema-check allowance are reverted, so the history
schema is exactly main's. stored_run_prompts instead looks up a batch of
files with one parameterized filename IN (...) query per chunk of at
most 500 names and matches in memory; the scan computes it once per scan
batch.

tests/test_api_admin.py

@@ -2466,6 +2466,7 @@ class TestActivityJobs(AdminAPITestCase):
             ambiguous=None,
             untraced=None,
             records=None,
+            history=None,
         ):
             key = Path(media_file).relative_to(self.output_dir).as_posix()
             outcome = names[key]