OpenReview api2 note-search index (venue + venueid per forum, mirrors DBLP for older venues)

Venue oracle for CS conferences. api2 /notes/search returns, per matching title, the forum's content.venue and content.venueid. For ICLR/NeurIPS/ICML/COLM/MLSys it returns the first-party value (e.g. 'ICLR 2025 Poster', 'NeurIPS 2024 poster', 'ICML 2025 poster', 'COLM 2025', 'MLSys 2025 withshepherding'); for ACM venues it returns a DBLP-mirrored note with venueid dblp.org/journals/PACMMOD/2025 or dblp.org/conf/SIGCOMM/2025. USED INSTEAD of trusting arXiv comment fields because this repo has already shipped venue attributions copied from those comments (see papers/sedd-score-entropy-discrete-diffusion, which claimed 'ICML 2024 per the arXiv comment field' for a paper with no venue in its comment field at all). The search endpoint tolerates title substrings, so exact-title matching is possible. It also surfaces REJECTED and WITHDRAWN submissions, which must be read as negatives not venues: SparseVLM carries an ICLR 2025 Rejected_Submission record alongside its real ICML 2025 poster record, and TurboRAG has only ICLR 2025 Withdrawn_Submission and ACL ARR 2025 May Submission records. Two different forum IDs under the same title usually means two submission venues, not one publication - resolve to the record whose venueid names the proceedings.