Document ingestion hardening: content verification for office formats + zip ingestion #16772

Summary

Findings from an internal document-ingestion research pass (docs/research/document-to-markdown-conversion-pipeline.md) comparing AutoBot's document conversion pipeline (media/document/, utils/document_parser.py, utils/document_extractors.py) against a reference document-to-markdown conversion utility. Two adoptable gaps, plus one pre-existing wiring gap surfaced incidentally while auditing format coverage.

Tasks

• Task 1: Verify ZIP-based office/ODF formats by content, not extension alone → child issue
• Task 2: Add zip/archive recursive ingestion for KB document uploads → child issue
• Task 3: KB upload allowlist omits already-supported office/ODF formats → child issue

Implementation Order

Wave: 1 (all three tasks are independent — no blockers between them)

Discovered During

Research pass, not a specific issue.