Missing all OLMo-3-1025-7B Stage 1 (pretraining) Olmo-core checkpoints

All 1415 stage 1 rows in src/scripts/official/OLMo3/OLMo-3-1025-7B.csv
(https://github.com/allenai/OLMo-core/blob/main/src/scripts/official/OLMo3/OLMo-3-1025-7B.csv) 404 while while every stage-2 (48) and stage-3 (12) checkpoint resolves fine. Tested with the script below

```bash
#!/usr/bin/env bash
# Shows that the stage1 (pretraining) Olmo-core checkpoints listed in
# OLMo-3-1025-7B.csv return 404, while stage2/stage3 return 200.
# Samples a few checkpoint dirs per stage and HEADs config.json in each.
CSV="https://github.com/allenai/OLMo-core/raw/refs/heads/main/src/scripts/official/OLMo3/OLMo-3-1025-7B.csv"
rows=$(curl -fsSL "$CSV")

for stage in stage1 stage2 stage3; do
echo "== $stage =="
# pick 6 dirs evenly spaced across this stage (endpoints included)
echo "$rows" | grep -oE "https://[^,]+/$stage/step[0-9]+/" \
| awk '{a[NR]=$0} END{n=NR; k=(n<6?n:6); for(i=0;i

Start with src/scripts/official/OLMo3/OLMo-3-1025-7B.csv and run the curl-based reproduction from the issue to compare stage1, stage2, and stage3 checkpoint URLs. Trace why the 1,415 stage1 entries return 404 while the other stages resolve. Done means the stage1 checkpoint URLs in the CSV resolve consistently with the stage2 and stage3 entries.

Escrita pelo modelo de indexação a partir do texto da issue.