- Registry-based model family detection (provider-agnostic)
- Variant and reasoningEffort ladder downgrade logic
- Three-tier resolution: metadata override → family heuristic → unknown drop
- Comprehensive test suite covering all model families
When an agent configured with variant: "max" falls back from Opus to
Sonnet (or Haiku), the "max" variant was passed through unchanged.
OpenCode sends this as level: "max" to the Anthropic API, which rejects
it with: level "max" not supported, valid levels: low, medium, high
The anthropic-effort hook previously only handled Opus (inject effort=max)
and skipped all other Claude models. Now it actively clamps "max" → "high"
for non-Opus Claude models and mutates message.variant so OpenCode
doesn't pass the unsupported level to the API.