The Discord /model picker built a single discord.ui.Select filled with
models[:25], silently dropping any models beyond the first 25. Discord
caps a single select at 25 options but allows up to 5 component rows, so
partition the list across up to 3 select menus (25 each; Back/Cancel use
the other 2) instead of truncating.
This fixes providers like Nous (curated list + Portal recommendations
exceed 25) whose tail — including free-tier :free Portal picks — was
previously clipped on Discord while showing fine in the Portal UI / CLI.
- _build_model_select: slice into <=25-option chunks, one select per chunk
(custom_id model_model_select_<i>), all via _on_model_selected. Multi-row
menus get a (n/total) placeholder suffix.
- _on_provider_selected: 'N more available' count reflects models actually
rendered across the partitioned menus.
- Add regression test covering the 37-model Nous case (no truncation/dupes,
per-menu 25 cap holds).
ab3e2f563b