DRS/Lear avoid double stamping on documents

- DRS already put certified copy stamp on served document. Config in DRS env var. Covers COOP-COOP_RULES, COOP-COOP_MEMORANDUM, COOP-COSD. All environments.
- legal-api ALSO stamp affidavit at serve time (Report._get_static_report, from PR #4627). Stamp on top of DRS stamp. Double stamp. Seen in dev.

Also gap: FILING_DOCUMENTS in legal-api/src/legal_api/reports/document_service.py have no COOP + COSD entry for affidavit. Only CORP + CORP_AFFIDAVIT. So ledger download URL for coop affidavit never get ?documentClass=COOP&drsId=DS... params. Wrong download path.