The #45954 model-dedup builds `user_models` from every is_user_defined
row, then strips those model IDs from every row where is_aggregator(slug)
is True. But is_aggregator() returns True for *every* `custom:*` slug, and
list_authenticated_providers emits named custom providers with slug
`custom:<name>` and is_user_defined=True. So a user's own custom provider
is treated as an aggregator and filtered against user_models — which holds
exactly its own models (the row helped build that set). Every model is
removed, the row drops to zero, and the provider disappears from the model
picker.
Guard the dedup loop to skip is_user_defined rows: a user's configured
provider is never an aggregator duplicate of itself. Built-in aggregators
(openrouter, etc.) are still deduped as before. Adds a regression test.
b7fa62c530