Greptile flagged that `models: []` / `models: "[]"` falls through the
non-empty allowlist gate and leaves the full live catalog selectable. The
symptom is real, but implementing the ask (gate on declared-ness instead)
measurably makes things worse: it emits an EMPTY picker and leaves the
provider unselectable.
Measured both branches against the real handler before deciding:
models key absent declared=False -> [chat-a, chat-b, image-gen-1, audio-tts-1]
models: [] declared=True -> [] EMPTY PICKER
models: "[]" declared=True -> [] EMPTY PICKER
models: [chat-a] declared=True -> [chat-a]
An unselectable provider is a harder failure than a few extra visible
models, and it is unrecoverable from the UI: `custom_providers` has no
WebUI write path, so it is hand-edited in config.yaml. There is also no
deny-all use case — a provider the user wants hidden is removed from
`custom_providers` outright, not left behind with an empty allowlist.
No production behavior change. Records the trade-off in the filter block
and adds `test_empty_allowlist_is_treated_as_not_configured` (native empty
list, serialized "[]", empty mapping, blank scalar) so a future "fix" of
this edge case fails loudly instead of silently emptying the picker.
Verified non-vacuous: applying the declared-ness gate fails all 4 new
cases with `assert [] == [...]`.
happy5318
88236dbc26