refactor(ledger): move report bundle download to GraphQL reportDownloadUrl

[jfrench9]

Summary

Mirrors the backend change (robosystems #762, closes robosystems#751): the report serialization-bundle download moved from the retired GET …/reports/{id}/download REST resource to the GraphQL read surface (reportDownloadUrl). Every flavor now resolves to a presigned S3 URL — JSON-LD is stamped at publish time, XBRL is materialized + cached on first request — so XBRL no longer streams a zip through the download endpoint.

Changes

• New GraphQL query (graphql/queries/ledger/__init__.py): GET_REPORT_DOWNLOAD_URL_QUERY + parse_report_download_url.
• LedgerClient.download_report_bundle (clients/ledger_client.py): reimplemented to resolve the presigned URL via GraphQL reportDownloadUrl, then follow it for the bytes — for both flavors. Signature and ReportBundleDownload return shape are unchanged, so existing callers (including the example demos) need no code change. format still accepts the "jsonld" / "xbrl-2.1" wire values (mapped to the JSONLD / XBRL_2_1 enum names sent as the GraphQL variable).
• Regenerated OpenAPI SDK: drops the dead get_report_bundle_download_url GET op and its response model. Also picks up incidental upstream description updates (create-taxonomy-block, create-information-block, schedule/entry request models) that the published 0.3.36 predated — not from this change.
• Tests (tests/test_ledger_client.py): rewrote the bundle-download suite for the GraphQL + presigned-URL flow (both flavors follow the URL; report-not-found and presigned-URL-failure paths).

Breaking change

None to the SDK's public surface — download_report_bundle(graph_id, report_id, format=…, to=…, expires_in=…) keeps its signature and return type. The behavior change is internal (GraphQL instead of the REST endpoint; XBRL is now a presigned URL rather than a direct stream).

Testing

• uv run pytest: 437 passed, 17 skipped (full suite).
• Pre-commit hook: ruff check + ruff format + basedpyright (0 errors) + pytest — all green.

Notes / Follow-ups

• After this is published, bump robosystems' pinned robosystems-client==0.3.36 to the new version (+ uv lock) and re-run the example demos to confirm end-to-end — the demo code itself is unchanged.