Shepherd PR #10401 to merge (ALL-875: collapse HIFLD ingest triplet)

PR #10401 (ALL-875 / ALL-845 PR3) collapses src/commands/search/ingest-*.ts triplet into shared ingestHifldDataset helper. Replaces failed task 1ebadcea-dd2e-481e-ae70-47267f6d5157 which hit max_retries=3 at 2026-05-12T03:15:34Z despite the PR being OPEN with all CI green and 0 reviews. CI fully green (build/test/apollo/codesmith/shadow-check/Vercel/CodeRabbit/Cursor Bugbot all SUCCESS). Awaiting CODEOWNER review.