The declared-provider-catalog note still recorded modalities as closed
because "nothing reads them: context.ts keeps only text blocks" — the
same reasoning this change disproves. Rewrite that fact in place, keep
pricing closed for its own still-current reason, and cross-link both
directions.
The new resolver cases never crossed the config schema, so neither
acceptance path this change adds had an executable gate: config.spec.ts
now refuses an unknown modality at both levels, pins the empty route
list to the namespace validator the settings seam actually runs, and
pins the `[]` materialization the inheritance rule depends on. A
catalog.spec.ts case re-asserts every rung through a written settings
section and `ctx.llm`, which is what the note's Testing section claimed.
Also export PiAiModality from the package entry — it types two public
config fields and consumers could not name it — record the unverified
declaration as a Known Limitation, and stop sharing one fallback array
across a route's models.
A model the installed pi-ai catalog does not describe was reported as
text-only with no way to say otherwise, so a vision model added through
the custom-provider form was refused at every image admission point.
The justification in the source described the DeepSeek chat-completions
serializer, which does reject image blocks; the pi-ai request converter
and every wire protocol it speaks carry images.
Modalities now resolve entry `input` -> installed catalog entry -> route
`defaultInput`, the chain the two capacity fallbacks already use, so the
route value is a fallback and never narrows a catalog model. Its default
stays `[text]`: nothing can interrogate a gateway for its modalities, and
over-claiming admits an image the provider rejects mid-turn, after prompt
admission has already committed the message.
