Injects `output_config: { effort: "max" }` via AI SDK's providerOptions
when all conditions are met:
- variant is "max" (sisyphus, prometheus, metis, oracle, unspecified-high, ultrawork)
- model matches claude-opus-4[-.]6 pattern
- provider is anthropic, opencode, or github-copilot (with claude model)
Respects existing effort value if already set. Normalizes model IDs
with dots to hyphens for consistent matching.