Did that 2025 assessment conclude that Iran was building toward a nuclear weapon, or didn't it?

The 2025 unclassified report does not assess that, but the 2024 one did. Money quote:

Iran has greatly expanded its nuclear program, reduced IAEA monitoring, and undertaken activities that better position it to produce a nuclear device, if it chooses to do so.

Also, that 2025 unclassified report was released before the June 2025 enrichment numbers I shared; these numbers would have influenced the report, and you dodged the question:

What's your justification for Iran producing 440kg of highly enriched 60% material, in secret deep under a mountain in violation of IAEA agreements, if not for a nuclear weapons program?