Now that each of these agents ships a native gpt-5.5 prompt variant,
their default OpenAI model is bumped from gpt-5.4 to gpt-5.5. The
gpt-5.4 entries are removed from the same-provider position in each
fallback chain (a single provider doesn't need both version entries -
if gpt-5.5 isn't available there, cross-provider fallback kicks in).
- oracle.fallbackChain: gpt-5.5 high (openai) -> gemini-3.1-pro -> claude -> glm
- hephaestus.fallbackChain: gpt-5.5 medium (openai only, requiresProvider)
- deep category.fallbackChain: gpt-5.5 medium -> claude -> gemini
- deep category.config: openai/gpt-5.5 medium
No changes to sisyphus, sisyphus-junior, ultrabrain, momus, or other
agents that still point at gpt-5.4; those stay on the shared regex-
based routing in the gpt-5-4 prompt family.