When the model dropdown sends a prefixed ID like "anthropic/claude-xxx",
AIAgent interprets the provider/model format as an OpenRouter path and
routes through OpenRouter instead of the direct Anthropic API.
Fix: read the configured provider from config.yaml model section. If
the model ID starts with the configured provider name followed by "/",
strip that prefix and pass the provider explicitly to AIAgent. This
ensures direct API providers (Anthropic, OpenAI, etc.) are used when
configured, regardless of the model ID format from the dropdown.
2864c2b691